Archos 5 Android (Gmail App Problem)

[Duoex]

Hello everyone. I'm having a small problem. I recently bought a used Archos 5 w/ Android Market Hack on it. However, when i tried to us the Gmail app, the previous owner's email was on it. I tried everything in my power to log out of the email but it's still synced to the phone. Does anyone know how to take out the previous email and sync it with my gmail? All help is appreciated.

Thanks,

Duoex