Tracking down why a study fails to solve/wierd issue

Can someone  suggest any method to figure out how to fix a problem I have been having.  for some reason, once in a while a study will fail to solve.  I immediately get the"failed to solve" error.  it is somewhat random, but after that happens, any study much more complex than a cube will fail. The only way to get any study to run successfully is to create a cube (or something similar) and run a study. sooner or later it will run successfully, and after that, all the other studies will also run successfully.  restarting/reboooting does not do anything.

sw2010 sp4

thanks
Greg

SolidworksSimulation