Hi there,
I'm having the exact same problem as 3mice but the advice from AlecStar does not resolve my problem, nor mugatu's MS KB link...
I'm running a 500+ client network, and this is at least my 3rd computer acting this way out-of-the-blue.
I reinstalled the other two, and my quess is that this is somekind of spy-/malware, possibly a virus, but non of the tools I've tried detect anything.
I'm running up-to-date Trend OfficeScan which didn't detect anything, I tried both Spybot and Adware SE, nothing...
Hope for a quick respons,
Regards, Bragi