I have a small assembly that keeps locking up SW for long-ish periods, maybe 60 seconds or more.  It was created to compare the before and after of a part being modified so it contains the 'old' version of the part, the 'new' version of the part aligned with the old, a 'mirrored' version of the new part assembled along side and an assembly cut to isolate the changed area.

While working on the assy, SW will go unresponsive randomly.  Sometimes it freezes after every click, sometimes I can spin several times or click on a couple things before it will freeze again.  I rarely can go more than 6-10 actions (spins or clicks) before it freeezes again.  If I suppress the cut, it works fine.

I have 3 separate but similar assemblies behaving the same way.

Anyone know what's wrong here?

It's a Dell T5500 running Windows7 Pro 64 bit, 6GB of RAM, 2.5 GHZ Zeon Processor and an nVidia Quadro FX 3800 driver 191.75 and I'm running SW 2011 SP3.