Moveing Sub Panels in FS9 with 2 Monitors

Can someone help me with a problem I am having?

I have a FS9 PC with two monitors, when running FS9 with say the PMDG 747-400 aircraft I have always been able to move the sub panels like the FMC, overhead, radios, throttles, etc. to the other monitor and re-size them there, but all of a sudden, I can't do that and I have not done anything or made any changes to cause this. Any ideas as to what I need to check or do to be able to once again move them to the other monitor?

I can drag things back and forth at the desk top level and in FS9 the cursser will go back and forth between the two monitors but I can't move the panels over to the other monitor.

Thanks

Bob Galbraith