major slowdown with gnome 2.4

[P draigBrady com]

After I upgraded my laptop from red hat 9 to fedora
my application is taking much longer to run.
http://www.pixelbeat.org/fslint/FSlint-2.04.tar.gz
If you extract that and run ./FSlint in the extracted
directory, on my fedora system it takes around 4
seconds (max CPU) to return after pressing the find button:
The pertinent fedora versions are:

    gtk2-2.2.4-5.1
    kernel-2.4.22-1.2115.nptl
    glibc-2.3.2-101
    pygtk2-2.0.0-1
    python-2.2.3-7

I confirmed this by mounting the exact same code
using NFS from another system (red hat 9) and I get
the expected runtime of around 1 second.

    gtk2-2.2.1-4
    kernel-smp-2.4.20-20.9
    glibc-2.3.2-27.9
    pygtk2-1.99.14-4
    python-2.2.2-26

The code forks off a child waits for data using
select(....,100ms).
If nothing is received after the 100ms it does this once:
while gtk.events_pending(): gtk.mainiteration(gtk.FALSE)

I tried changing the 100ms to a much larger timeout
to no avail.

Another clue is that the first run is sometimes quite quick,
but subsequent runs slow down, which may suggest a kernel
scheduling issue?

Note also that the forked child itself forks a few
processes, but testing this child in isolation
showed no slowdown.

Any ideas appreciated.

thanks,
PÃdraig.