OK, tried Opera browser, and I have the same problem. So it is not my AV, or MSIE (Opera shows the same issue).
I am not sure what has happened. I have installed MSIE ver 7, Kaspersky ver 7, and now, I cannot delete messages at comcast.net webmail. I uninstalled Kaspersky. Still no good. I do have spybot s&d installed. Its a new OS install. All critical updates are in place. An interesting side note is that if I log into the kids account, I can fully manipulate comcast webmail. Just not from my account (cannot delete messages). I have tried to purge cookies, files, history. No luck. I am suspecting some security setting. Any ideas?