>Thanks, Lex and Andreas, for your hunting!  I'll go back to trying to
>figure out some way of replicating the bug reliably -- or getting rid of it
>:-)

Just to tie up this thread (no pun intended!), Bijan Parsia figured out the
bug in the PWS that was causing the symptoms that led us to believe that
Squeak's FileStreams were not thread-safe.  It was a simple
open-without-close bug, but it a long time to find.  For those who are
using PWS/Swiki, the fix is at
http://www.cc.gatech.edu/fac/mark.guzdial/squeak/pws/131updates.html

Mark

--------------------------
Mark Guzdial : Georgia Tech : College of Computing : Atlanta, GA 30332-0280
(404) 894-5618 : Fax (404) 894-0673 : guzdial at cc.gatech.edu
http://www.cc.gatech.edu/gvu/people/Faculty/Mark.Guzdial.html