Auto-hide for vista toolbar... broken

[Stormy Fairweather]

One of the settings for windows I like is to auto hide my toolbar, so that it comes up only when I need it. And this feature has worked properly fo some time now. But recently it has stopped functioning. There has been no changes in hardware, no new programs have been installed.

When the toolbar comes up, it stays up. It no longer 'hides.' If I disable the option, and re-enable it, the toolbar hides, until the next time it is brought up, and then it remains. Resetting does not resolve this.

Any ideas?