Hey all,
So my pthread crash was solved by changing to a self compiled 2.6.13 kernel with ck patches applied.
So for all those googlers in the future my configuration is:
AMD64 3200+ a8v mainboard, nvidia N6600 gfx, 1GB RAM, 2.6.8 kernel running debian sarge and glibc 2.3.2 and 2.3.5. If your machine looks like this and your pthreads are crashing try changing to a 2.6.13 kernel.
Thanks again to all for the efforts, especially the folks on the glibc list and Johannes, who helped me a lot with debugging this issue.
B.