I edited email.apk and now having an issue..

[sniffs]

I copied off email.apk to my sd card, edited it on my computer(changed the notification logo) and then signed the file and put it back in /system/app and yet it's gone from my app list.

Did I do something wrong? This has worked with other apps.. are the stock google apps different?

edit: interesting.. renamed email.apk to email.bak and then renamed it back and its working.