Could you please uncheck the box saying Use Graphic Proccesor under Lightroom Preferences > Performance panel and check if it helps.
Do restart Lightroom once you make the changes.
Thanks for the reply. I tried that and it didn't do anything to help.
all the sudden the develop module becane completely greyed out for all of my photos, in every catalog. Only the photo itself is displayed.
Do Window > Panels > Show Left Module Panels and Window > Panels > Show Right Module Panels (or hit the Tab key).
That did it! Thanks for the help you two. Interesting how that happened, I've never tampered with this setting.