AssoEdit: Looping on ADD...

I am attempting to ADD a File Association by File Filter to an eCS 2.0 
RC2 system that is running fine except for the below:

I've never had a problem before, but now trying to add:
     *.WMV  [The actual pattern is not significant.]
to the list, the system goes into a loop.  One of the two processors 
starts running about 80-90%.  Most of the processor is going to:
     CPU0-IRQ Load

The only way to exit is  Ctrl-Esc and CLOSE the task.  The task closes 
clean.

Any idea what could be wrong?
-- 
TIA,