Im running CyanogenMod 5.0.5.7 with BlackIceTheme right now and im wanting to switch to NexTheme 2.0 so just switching themes not roms i went ahead and downloaded it on rom manager and installed it without wiping data/cache when the phone rebooted it had no signal and still had part of the BlackIce theme and parts of nextheme so no i need to wipe data/cache before installing this theme