Editing RRC 4.0 Process Diagrams freeze browser (IE and Mozilla)

 I have installed supported version of IE (9) and Mozilla (3.6.28).  Both have the RRC plugin installed.  When editing diagrams, the browser takes all the CPU utilization and will occasionally freeze.  I noticed the issues is more prominent when the "Connector" is selected vs. the pointer - or related to changing between pointer/Connector.  Sometimes if I wait (1-2 minutes) the CPU will eventually return to normal.  However, often the CPU will spin forever until I kill the browser process.  I also see a huge amount of page faults in the browsers (both) while the CPU is spinning (5-6K new page faults/sec) despite the fact that there is 1G of available memory. The problem appears worse in IE than Mozilla, but appears in both.