Sawfish wm won't start from gdm3

[Rick Macdonald <rickmacd@shaw.ca>]

I recently (finally) upgraded from lenny to squeeze. All seems well 
except if I choose the sawfish window manager from the gdm3 greeter, the 
dialog goes away and it just sits with the debian logo and the stars 
background. I can't find any error messages anywhere (~/.xsession-errors).

If I start up gnome with the default wm, metacity, I can kill metacity 
and run sawfish from an xterm:

killall metacity; sawfish &

Any ideas why it won't start from the gdm3 greeter?

Regards,
Rick