Thank you for the suggestions.
I upgraded my client to 7.0 SP2 beta. I also upgraded IE to the latest. The behavior was the same. I then uninstalled studio and replaced with runtime. Bingo! Problem solved. Reinstalling studio made the the problem return. Is there a problem upgrading from runtime to studio maybe? At least I am relatively sure that the problem is specific to my PC. I am getting ready to install on ~1500 workstations in a couple weeks.
Here are some other things I have noticed:
After the screen blanks, if I maximize the Window the web page will be displayed properly. If I restore the Window it will go blank again.
I can maximize C1 in front of the GW client. The web page will be displayed for about a 10th of a second when C1 is then minimized.