GPRS/Data only starts after reset
Backup your data and factory reset your device. If problem is intact, its firmware issue. Fixing it isn't easier than flashing new ROM.

The best way to work around: Disconnect Mobile Data by renaming APN. No need to factory reset or to flash new ROM. You don't need to rename APN manually. Install Widgetsoid and use its mobile data toggle widget. In settings, make sure toggle method is APN renaming. Done!