Very weird problem with amavisd-new crashing

[elekktretterr at exemail.com.au]

Ok, the problem seems to be with libc_r. switching to libthread_xu works.
perl makes this error:

neptune# Fatal error 'mutex is on list' at line ? in file
/usr/src/lib/libc_r/uthread/uthread_mutex.c (errno = ?)
Fatal error 'mutex is on list' at line ? in file
/usr/src/lib/libc_r/uthread/uthread_mutex.c (errno = ?)
Fatal error 'mutex is on list' at line ? in file
/usr/src/lib/libc_r/uthread/uthread_mutex.c (errno = ?)
Fatal error 'mutex is on list' at line ? in file
/usr/src/lib/libc_r/uthread/uthread_mutex.c (errno = ?)
Fatal error 'mutex is on list' at line ? in file
/usr/src/lib/libc_r/uthread/uthread_mutex.c (errno = ?)