incrediBILL - 8:31 am on Dec 26, 2010 (gmt 0)
Have you tried it from a different location?
It's possible your ISP is suffering intermittent packet loss.
For instance, when I see an issue on Comcast, I also check using my Sprint Broadband connection to see if it happens there as well.
Try a traceroute from your PC to your site a few times and see if you're dropping packets.
You may find out it has nothing to do with your server.