My best guess is a buddy of yours figured out your password. Try changing it and see if that stops it.
Or see above.
Bob's Law: The rationality of a person is inversely proportional to the number of political and religious bumper stickers on his car. Around bumper-sticker warriors, smile, speak calmly, and get the hell away as fast as possible.
Does this happen without even making edits to your profile? Every time I change my profile firefox used to (not anymore) saves the password of one of the fields making me have to remove it every time as I I hit submit.