Rick,
I found this in a thread at MacIntouch. Maybe it applies to you?
QUOTE
You can change the Comcast home page, The trick is
to make sure your not running any other MS app's like Entourage namely. Explorer and Entourage share some of the some preference files and any changes made to your home will get changed back if Entourage is running.
Do a clean reboot, make sure Entourage is not running, change your home page and it should stick.