Running UBB Classic 6.7.2

I'm having a problem in searching the member list from within in my control panel. In searching for an individual member, I get the appropriate input screen. But when I add search criteria and click "Begin Search", I am returned to the Log In screen where I am asked for my username and password. If I submit username and password, I'm returned to the Control Panel home screen. (Even if I don't submit UN and PW, I am still logged on to the control panel with just a blank screen.)

Anyway, if I then return to Member Management / View/Edit Members, the process repeats itself and becomes cyclic. The prebuilt searches "Inactive Members", "Last 50 Registrations" , etcetera seem to work okay. Also, I can access an individual member record from their link on the board proper. That works fine and takes me directly to the members record. However I can go no further than that. If I try to do an additional search while I'm in the control panel. I enter the routine described above.

Any ideas why I can't execute an individual (or group for that matter) search from my control panel?

Thanks -- Hal