logic pro: can't close, save or save as - after upgrade to snow leopard! any advice?

Hi guys

I just upgraded from leopard to snow leopard (10.6.8) and now my Logic projects won't close, save or save as. Logic crashes if i click save as - and otherwise i have to force quit it.

Furthermore, my Apogee Duet sound card keeps disconnecting on it's own - it just vanishes from view and the computer switches to the monitor display audio.

Can someone please help or advise me who to contact about these problems??