Xmarks Authentication popup window
In the past two days a tremendously annoying popup window has started showing up about every minute and a half. It is labeled "Xmarks Authentication" and it asks for a username and a password. I don't have any idea where it came from. I have run a McAfee scan with no result, and have searched the hard drive for "Xmarks*" and found nothing.
Any help getting rid of this nuisance would be much appreciated.