No, nothing like that. The only AV I am running is AVG, which doesn't mess with network connections.

It just happened again, for the second time today. This time I did some sniffing.

Using Ethereal I could see that neither IE or Firefox were even managing to send a TCP SYN request. There was no data being sent at all.

At the same time I could telnet to port 80 on www.empegbbs.com just fine and that showed up in the Ethereal trace.

So it would look like there is a problem at the WinHTTP level, but I would be surprised to find that Firefox used that ? I would have imagined that it did all its own HTTP handling and didn't rely on the Windows WinHTTP code.