I run up2date, the GUI window pops up saying its a beta release, then I hit ^C on the terminal I started up2date on. In the terminal window, up2date seems to exit, but the GUI window stays there.. I hit 'OK', and it spits the beta message out to the terminal, then the GUI keeps running like nothing happened. When I hit ^C, I expect the program to completely exit, not just pretend to.
The beta window which is popping up is not a permanent part of the up2date/rhn_register routines, so anything unusual that you are seeing with respect to that window is really low priority, seeing as it will go away here shortly. Closing out as not a bug since that's not a permanent part of the routines.