I am having issues with moving parts around in an assembly.  When I click on a part face and drag to move the part, there is about a 10 sec. delay before the part actually moves.  Also, while adding mates to parts, there is a delay before the part moves into place and if I try and move components that have distance limit mates the move is not smoothe but very slow and choppy.  Is this system memory related, video card or some other culprit?  I am currently running Vista X64 with 4 gig of ram and am in the process of upgrading to 8 gig of ram.  Video card is an ATI Fire Pro 5700.  Just curious if anyone else has these problems?

Thanks,

Kevin