I know of several other people having the same disconnection problems with Comodo. We switched to Zone Alarm and it works fine.
Be sure to uninstall Comodo if you decide to try ZoneAlarm. Comodo seems to be harder to configure.
http://www.majorgeeks.com/ZoneAlarm_Free_d388.htmlSelect the
Author's Site under
Free Downloads From: in the center of the page. Hold down your
Ctrl key before you select the author's site so that it will allow the download if you have a popup stopper. Keep holding Ctrl until the save box appears.
Someone else may be able to help you with the Comodo settings, I haven't had any luck on that, I think Zone Alarm is a better firewall anyway.