I experienced 3 CTDs in certain places. One of them was the Arboretum Hotel CTD.

Strangely, when I started The Gravefinder's Repose and went into Moss Rock Cavern, it would load to 1/3 then CTD. I also experienced this when exiting Fatback Great Chamber. It would load... then CTD. I dunno where others can crash. So far, these are the CTDs that I encountered.

I have a modded game.

BTW, why does Oblivion crash every now and then?

System specs? Oblivion version? Loaded mods? When did it start happening? MMM by any chance?

Specs:

Intel Core2Duo E6320
Kingston 2GB RAM
Inno3D GF 8500 GT
Asus Motherboard

Oblivion 1.2.0416

I have OOO, MMM and a lot of other mods. I will post the Load Order later.

1st crash: Gravefinder's Repose: Once I recieved the quest, I went to Moss Rock Cavern. It loaded upto 1/3 then it crashed.

2nd crash: Fatback Cave, no quests: Cleared the cave of goblins (a lot of them), looted everything from all 3 levels. Had a CTD after loading the first level of the cave (I was going to leave the cave at that time)

Just a hunch, reinstall without MMM. Dunno what it is about that mod, but it seems to frequently screw up people's games. I'm tempted to think it has to do with the changes they made to many of the default creatures (skeletons, and goblins who summon skeletons for me) that just screws things up royally.

OOO and MMM conflict, don't they? There was a fix for it though.

Now it also happened in Akaviri Kojima. Awww...

Ive been running MMM for a good while now, havnt experienced too many problems, i load it last (before deadly rexlex though) =\

And yes, check for conflicts with your mod list, that could solve your problems.

The Arboretum Hotel CTD seems caused due a conflict between BC and OOO. But in the last version it seems resolved (I use OBC though..!). For the others CTD try downloading and installing the UOP3, just released. They say this could resolve many CTDs..

Look for commonalities. If something is causing all these problems, it's likely all the same thing. It might have not been noticed before due to being a different level (and thus some things not being spawned).

Load Order:

Oblivion.esm
AWS-Core.esm
Kvatch Rebuilt.esm
HorseCombatMaster.esm
Toaster Says Share v3.esm
Better Cities Resources.esm
Mart's Monster Mod.esm
Mart's Monster Mod for OOO.esm
TamrielTravellers.esm
DremoraCompanion.esm
Cybiades.esm
Cobl Main.esm
Jog_X_Mod.esm
nVidia Black Screen Fix.esp
Natural_Vegetation_by_Max_Tael.esp
Natural_Habitat_by_Max_Tael.esp
tag_NaturalWildlife.esp
oc_darker_nights.esp
SkingradBridgeLights.esp
Cities Alive At Night.esp
IWR - Windows Lights Shutters - Optimised.esp
AliveWaters.esp
AliveWaters - Koi Addon.esp
AliveWaters - Slaughterfish Addon.esp
Real Lava 1.3.esp
JolardHome.esp
AkaviriKojima.esp
arme - excalibur.esp
PhoenixEquipment.esp
Dragonbone Armor Set.esp
rdweaponpack1.esp
samurai.esp
mythsandlegends.esp
ExnemRuneskulls.esp
Doomshard Bow.esp
Lost Paladins of the Divines.esp
Adonnays Elven Weaponry.esp
DMACArmor.esp
The Dead Knights.esp
Armory of the Silver Dragon.esp
Sauron_Armor_Chest.esp
Thieves Arsenal.esp
tda_ScytheModv1.2.esp
Daedric Lord Armor.esp
Imperial Watch Playable Fixed Gauntlet Texture.esp
Dragon Knight Armor v. 1.1.esp
Klarre Forestheart.esp
blacktempler.esp
Bob's Armory Oblivion.esp
RealSwords - Khajiit LO-NPC v1.3.esp
RealSwords - Orc LO-NPC v1.0.esp
RealSwords - Argonian LO-NPC.esp
RealSwords - Redguard LO-NPC.esp
RealSwords - Bosmer LO-NPC.esp
RealSwords - Breton LO-NPC.esp
Akaviri Imports.esp
ExnemZorlackArmory.esp
New Frostmourne Sword by Jojjo v1_0.esp
pale_rider's Paladin Equipment_enchanted_eng.esp
pale_rider's Armory of the Berserker.esp
FF_WaldnirsWoods.esp
MountainTower.esp
KumikoManor.esp
MidasSpells.esp
Amajor7 Imperial Furniture.esp
Visually Enchanted 2.1.esp
attack and hide medium v2.1.esp
StealthOverhaul.esp
RealisticForceMedium.esp
RealisticMagicForceLow.esp
Adrenaline Fuelled Archery- Bow Sway.esp
Living Economy.esp
RealisticFatigue.esp
Crowded Roads.esp
Salmo the Baker, Cobl.esp
ND_LongerSummons_x2.esp
Ayelid Wells.esp
ChaseCameraMod.esp
TTHealthRegen.esp
Cliff_RankDependantArenaSpectators.esp
DropLitTorchOBSE.esp
DA ReducedBackwardsRunningSpeed.esp
DA Sprint.esp
PersuasionOverhaul.esp
Jump_Adjustment-2211.esp
RenGuardOverhaul.esp
Update My Statue.esp
FF_Horse_Whistle.esp
DecoratorAssistant with OBSE v1.1.esp
[GFX]_Initial_Glow-all.esp
Quest Award Leveller.esp
Oscuro's_Oblivion_Overhaul.esp
OOO-DLT_Immersion.esp
OOO-Respawn_Week.esp
OOO-Magic_Script_Effect_Fix.esp
OOO-Magic_Effects+Enchantments.esp
OOO-Magic_Effects+Spells.esp
OOO-Magic_Game_Settings.esp
Denock Arrows.esp
OOO-ThiefGuild_Difficult.esp
OOO-Water_Weeds.esp
OOO-Armor_Perks_WearRate_Repair.esp
OOO-BirthSigns.esp
OOO-Combat_Skills_Perks_Marksmanship.esp
OOO-DaedraLord_Quests.esp
OOO-Dangerous_Traps.esp
FineWeapons for OOO.esp
RustyItems for OOO.esp
Harvest [Flora].esp
SupremeMagicka.esp
SM_EnchantStaff.esp
SM_OOO.esp
SM_DLCSpellTome.esp
Mart's Monster Mod - Diverse Creature Skins.esp
SM_UnlockSpells.esp
Mart's Monster Mod for OOO.esp
Mart's Monster Mod - Diverse Imperial Armor.esp
Mart's Monster Mod - Additional Enemy NPC Vars.esp
Mart's Monster Mod - Hunting & Crafting.esp
Mart's Monster Mod - Gems & Gem Dust.esp
Mart's Monster Mod - Looting NPCs & Creatures.esp
Mart's Monster Mod - More Wilderness Life.esp
Mart's Monster Mod - Less Bone Loot.esp
Mart's Monster Mod - Resized Races.esp
Mart's Monster Mod - Foxes.esp
Mart's Monster Mod - Vindasel.esp
Mart's Monster Mod - Extra Wounding.esp
Mart's Monster Mod - Dungeons of MMM.esp
Mart's Monster Mod - City Defences.esp
Mart's Monster Mod - No Undead Rise.esp
SM_MMMCompatability.esp
Kvatch Rebuilt.esp
Kvatch Rebuilt - OOO Compatibility.esp
DeadlyReflex - Combat Moves.esp
Mounted_Spellcasting Deadly Reflex Compatible.esp
EnchantedGems_Geomancy.esp
Knights.esp
DLCOrrery.esp
DLCThievesDen.esp
DLCFrostcrag.esp
DLCVileLair.esp
DLCMehrunesRazor.esp
DLCSpellTomes.esp
DLCHorseArmor.esp
Knights - Unofficial Patch.esp
DLCOrrery - Unofficial Patch.esp
DLCThievesDen - Unofficial Patch - SSSB.esp
DLCThievesDen - Unofficial Patch.esp
DLCFrostcrag - Unofficial Patch.esp
DLCVileLair - Unofficial Patch.esp
DLCMehrunesRazor - Unofficial Patch.esp
DLCSpellTomes - Unofficial Patch.esp
DLCHorseArmor - Unofficial Patch.esp
Harvest [Flora] - DLCVileLair.esp
Harvest [Flora] - DLCFrostcrag.esp
Quest Award Leveller - Vile Lair.esp
Quest Award Leveller - Mehrunes Razor.esp
Quest Award Leveller - Knights of the Nine.esp
Servant of the Dawn.esp
300_White Stallion 4.esp
Origin of the Mages Guild.esp
The Lost Spires.esp
TOTF.esp
CybiadesDungeon.esp
bartholm.esp
WeaponsOfTheNine.esp
SentientWeapon.esp
SentientWeapon - OOO & MOBS.esp
Ruin.esp
DremoraCompanion.esp
Enhanced Quest Roleplaying.esp
Ungarion1TheWelkyndSword.esp
BladesSmithyOOO.esp
300_Caldera.esp
Mighty Umbra.esp
NakedNord.esp
thievery.esp
ChangeinManagement.esp
LastUnicorn.esp
Artefacts of the Ancestors.esp
AyleidArrows.esp
Hand of Dawn.esp
Hand of Dawn - ONE.esp
Kobu's Character Advancement System.esp
Kal's Skill Overhaul - Bofra's x3.esp
Toaster's Legendary Mastery.esp
Toaster's Legendary Skills.esp
Level_Rates_Modified_x3.esp
Better Cities Full.esp
Better Cities - Full Additions.esp
Better Cities - LS RTT TotF.esp
Better Cities - Full City Defences.esp
AnvilBayExpansion.esp
Better Cities - Tears of the Fiend.esp
Better Cities - Anvil Bay Expansion.esp
WBA Arboretum.esp
IWR-Windows.esp
TamrielTravellerAdvScript.esp
TamrielTravellers4MMM.esp
TamrielTravellersItemsCobl.esp
TamrielTravellersItemsVendor.esp
KT_CustomRaceFix.esp
Slof's Playable Xivilai.esp
Kikai-PlayableDremora12.esp
_Ren_BeautyPack_full.esp
AinmhiRace-RensBeautyPackFull.esp
xulAncientRedwoods.esp
xulAncientYews.esp
xulArriusCreek.esp
xulPatch_AY_AC.esp
xulBeachesOfCyrodiilLostCoast.esp
xuldarkforest.esp
xulColovianHighlands_EV.esp
XulEntiusGorge.esp
xulImperialIsle.esp
ULFallenLeafEverglade.esp
xulLushWoodlands.esp
xulRollingHills_EV_withoutWheat.esp
xulStendarrValley.esp
xulTheHeath.esp
OOO-Potions.esp
Cybiades.esp
Alternative Start by Robert Evrae.esp
Dark Dungeons.esp
Streamline 3.0.esp
OOO 1.32-Cobl.esp
Cobl Glue.esp

That's quite a lot of mods.

Indeed it is, Try moving Marts Monster mod down to just above the unique landscapes. and then OOO right above...or below that. (Sorry i dont use OOO..)