internal error: startTask: Can't create new task

internal error: startTask: Can't create new task

With
ghc-6.4.20050506-src.tar.bz2
Fedora Core 3 (current updates) (gcc 3.4.3 glibc 2.3.5)
amd64
perl v5.8.5 x86_64-linux-thread-multi
pugs r4695

I built ghc-6.4.20050506-src by doing:
./configure
make
make
make install

You can build pugs by doing:
svn co http://svn.openfoundry.org/pugs/ -r 4695
cd pugs
perl Makefile.PL
make unoptimized

To generate error,
EVALBOT_CODE='42' EVALBOT_TMPFILE=/tmp/deleteme EVALBO
T_PUGS=`pwd`/pugs perl -w examples/network/evalbot/evalhel
per.p5 ; cat /tmp/deleteme

Error:
$ cat /tmp/deleteme
pugs: internal error: startTask: Can't create new task
    Please report this as a bug to
glasgow-haskell-bugs@haskell.org,
    or http://www.sourceforge.net/projects/ghc/

Fyi.
Thanks for all your work,
Mitchell Charity
mncI02eyA zap vendian zot org