execute-with-interface in "stressed" situation

hi,

I'm using LW 4.2.7 on linux and windows.

It appears to me that LW slows down and even sometimes crashes if
cpu activity is very high and the interfaces get a _lot_ of things
to do queued up with execute-with-interface. 

How does this queuing work? Can I tune it somehow? Can I inspect
it from my programs?
-- 
  (espen)