Not Shorpy's problem, not Comcast's problem.
I finally got around to doing some investigating. First I tried a WiFi access point on a different gateway to the Internet. Shorpy worked. Then I used my neighbor's unencrypted WiFi, which is on Comcast. Shorpy worked!!
So the problem lies with my cable modem / router. Multiple PCs using this modem/router all have the problem.
Thank you all for your responses. I should have been looking closer to home. I have cycled the power on the modem/router, but that hasn't fixed the problem.
seacue