I don't either... but I usually always place them back into an update.zip to intall...but try to install that unsigned system APK by trying to launch the APK itself, it won't install... so I'm thinking that is why thebowers stated to sign all APKs anyways, that's my guessI'll jump in here, too. I don't ever sign system apps either. I've never had a problem, but I probably just jinxed myself.