Our group recently upgraded to 2011 sp.1 from 2010 sp.4. We are experancing a lot of lag when we are working on previos version created assemblies. It is seen the most when appling mates, up to 30 seconds of wait time when changing, applying or creating mates. I created a basic assembly from scratch in 2011 and did not see this lag and I have never experianced this type of lag with solidworks. Any help would be greatly appriciated.