Wierd. There's two separate places in the dang idle loop that should be
checking for the timer interrupt which really ought to be a pretty solid
guarantee of catching it on pretty fine boundaries. If you really want
to follow up on this, I'd suggest adding a counter to keep track of how
many times the interrupt check is tickled between you wanting to exit
and an actual exit. That might give a clue. Adding an interrupt check in
yet another place is not a solution I like the sound of.

tim

-- 
Tim Rowledge, tim at sumeru.stanford.edu, http://sumeru.stanford.edu/tim
Programming just with goto's is like swatting flies with a sledgehammer.