Updated my white 64gb by flashing both the system and emmc with images for my product from Navifirm (Nokia Suite). After that I restored my contacts, notes, calendar and messages through PC Suite (yes, PC Suite). Copied all my content files to the emmc from my PC right after and installed all my apps afterwards. Never had issues nor lags since I started using it again (although some apps and tweaks no longer works). My variant is PR1.2 (30.2012.07-1_PR_005).