Do you have a Winmodem...or a hardware modem. the fact that it's locking up the computer makes me think it's a winmodem that is causing the problem, but i'm not sure of any real quick disconnect routine
I'm using an Intel 56K Hardware modem (V92). It's a new computer and thus a new modem, but I didn't have this problem with the same ISP connection with my old Sportster 56K hardware modem.
I've tried setting the redial times at zero, and I've unchecked the "redial if line is dropped" toggle in the modem settings. When I click to disconnect, it sounds like it's instead trying to log back in several times, but it's a mystical mystery to me why my modem seems so attracted to the darn ISP--they're like teenagers in love.
Any thoughts on why it might try to keep dialing? Any connection between this problem and Outlook Express settings?