Freezes

[FreezeProblem]

Hi All.
I encountered some problem which is: game freezes sometimes(often and randomly). I may play 1-3 hours and all is ok, but sometimes it halts dead. Sometimes often. Only thing I can do when it happens is to kill process. First this happened when I exit starting mine. I exit, autosawed, and after 1,5 seconds freezed. Nice begining . Now I play about 14 hours total and this happened few times (more than 5 less than 10). It may happen even inside building where load on system is minimal.
What can be done about it?
Before that in russian version it happened only 2 times in 30 hours playtime but there were often crashes on entering doors. I deleted it anyway because of bad translation and now playing english version. When deleting prev version I also deleted all related data in "My Documents" so it had no link with current english version with latest patch.

I disabled postrender effects(no blur and no hdr) and disabled distant smoothing (forgot how its named) but it still freezes. Also disabled shadows.
System: Win 7 x64, AMD Phenom II x4 3.2 Ghz, 8 Gb RAM, GeForce GTS 450.

PS sorry for bad english.

[FreezeProblem]

UPD I disabled automatic memory purge and there was no freezes for last 8 hours (and no crashes). May be lucky random, but I still saving every few minutes in different slots.

UPD2 no freezes since I disabled memory purge. Crashes even more rare than original oblivion (which crashes nearly 10% when openinig container or corpse). Nehrim does not have such problem.