Network crashes while using location services on jailbroken iOS 5

[Umer]

I hav an iphone 3GS running untethered jailbroken iOS 5, im lucky to hav untetherd jailbreak as my 3GS has old bootrom, but im facing a serious prob on iOS 5 i.e my network crashes after sometime, everytime i turn on the location service! and if i keep the location service on,network keeps crashing after every minute or somthing....
please tell me how to get rid of this problem!

[saving107]

Restore, Set up as new.

[Umer]

Restore, Set up as new.

i cant do the the normal restore thing as i hav to preserve the unlockable basband but i repeated the whole jailbreak process, still the problem remains as it was!

[saving107]

Restore = phone that works

No Restore = phone that doesn't work