I keep getting gmail alerts every few hours when I'm logged into my gtalk account, and they are starting to really irritate me. I tried going into the Gmail connection prefs, but the checkbox to turn off mail alerts is disabled (but the option is enabled)...
you've got your gtalk account configured as a Jabber account. Jabber doesn't actually support mail notifications... but a bug makes it be forced on for gtalk.
Recreate the account within Adium as a Google Talk account; you'll gain control over that preference.
