[JDEV] Server crashing in pth_sched.c (on Mac OS X) : help needed

[Jabber Developer]

Hi

I am still trying to have jabber running correctly on Apple Mac OS X.
I turned on the debug mode in the pth_library and added some extra log 
in pth_sched.c
I can reproduce server crashes really often and it's always crashing 
while executing :

     pth_sc(sigprocmask)(SIG_SETMASK, &pth_sigblock, &oss);

in the function : intern void pth_sched_eventmanager(pth_time_t *now, 
int dopoll)

I know it's crashing there because my code now looks like :
         pth_debug1("******** allow delivery (sigprocmask)"); // funcall
     pth_sc(sigprocmask)(SIG_SETMASK, &pth_sigblock, &oss);
         pth_debug1("******** end allow delivery"); // funcall

I can see in my log the first log, but the second message never appear!
Is it nornal that the variable oss is never initialized in this 
function ? It looks weird to use a non initialized variable. My system 
is not using syscall() but instead directly sigprocmask, can someone on 
a linux/solaris system check how this pth_sc(sigprocmask) is defined?

Any ideas/suggestions why it's crashing here??

Thanks!