magic attach, quit frees stuck nptl?

[greg]

hello,

i'm getting hangs several times daily on various threaded apps under
redhat 9.  more often than not when it happens i can break it free by
attaching from gdb, then merely quitting gdb!

how can this be?

i suspect a nptl scheduling bug.  i've filed:
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=107900
but alas so far no response, nor to posts on redhat-list.

i don't know how to proceed, any suggestions?

tia,
greg