Quite possible - this system had a filesystem corruption (due to faulty RAM)
about two months before. Some files were suddenly directories, trying to
remove them caused rmdir to hang so that even kill -9 didn't work, etc.
The system was then rebooted and fsck had to be run manually, but it seemed
to fix all problems... SIMMs have been replaced (all four, 4M*9 each, were
bad!) but a rarely accessed directory somewhere on the disk could still be
corrupted.
Thanks again for looking into this problem.
Marek