Did a little experimenting this morning, here are results in no coherent order:
(1) The problem may be when I try to reach the forum - I was able to poke around the main website and the wiki, but shortly after opening the forum all universal-devices.com becomes unreachable via web browser. I haven't tried this often enough to be scientific, but it seems like the forum webpage triggers the oroblem.
(2) When universal-devices.com is unreachable via IE it still responds to ping from a command prompt, so it is not likely a DNS error.
(3) I downloaded Firefox. If the universal-devices.com is in the unreachable state it is also unreachable from Firefox. However, I haven't been able to go into the unreachable state from Firefox, just from IE.
(4) The only way to reach universal-devices.com after it enters the unreachable state is to wait. Rebooting the PC does not help. I haven't studied the wait time, but rlav's estimate of 10 minutes seems about right.
(5) I also tried rebooting my router - didn't help.
Could this be a Comcast problem?
I guess for now I will try Firefox to access universal-devices.com. I probably won't get a chance to try anything more for at least a week as I am going out of town.