From time to time we run into the problem that /dev/urandom (and also /dev/null) has wrong perms after system boot

sisis@sunny1:> ls -l /dev/urandom
crw-rw---- 1 root root 1, 9 22. Mr 10:23 /dev/urandom
and causing all kinds of, for example SSL problems. The fix is simple, but why happens this at all? I checked already
all start scripts we provide and which are called at boot time without any luck. Don Google shows, that we are not allone with this, but
I have found only pointers to Ubuntu systems.

I have seen this inhouse on some of our SLES 11 development servers and some day ago as well on a server of one of our customers.

Any ideas? Thanks in advance