possible bug : choosing Einstein's "show graphics" options freezes the calculation

For how long did you keep the graphics window open? I would assume that the process counter would increase _very_ slowly, but not actually freeze.

To me this looks like you have a graphics card without (or non-working) hardware-accelerated OpenGL and the OpenGL graphics done by the CPU eats up all the cycles, leaving nothing for the worker thread ("crunching").

BM