I have an unlocked Nexus One that I rooted to remove a system application (Twitter), but now the OTA system update fails with the message
Verifying current system ... assert failed: apply_patch_check("/system/app/Twitter.apk", "<long hex string>") E:Error in /cache/c8847c98b948.signed-passion-FRG83-fromFR91.c8847c98.zip (status 7)
Un-rooting the device doesn't seem to fix this. Is there more to removing a system app than doing a 'rm' of the .apk? For example, is there some configuration file that also needs patching?