Again , I appreciate the suggestions, I think we can rule out the processor and the video card since this is a new problem that just started happening. The MS update on the printer drivers is definitely worth pursuing. I may let the Citrix engineers deal with this because on our Citrix servers (virtual W2008) the app works fine when run via Remote Desktop but behaves badly when run on the same computer when run via Citrix. Hopefully this will bruise their ego's enough that they will dig in!
All the best,
Mark