Hmmm. After a hard reboot, all shared memory should have been cleaned up anyway.
By the way, you shouldn't use a file on disk to store the scoreboard data. Shared memory is faster.
If ipcs (run as root) doesn't mention the shared memory, then your process doesn't have access to it, or, more likely, it simply doesn't exist. A hard reboot should have cleaned it up, so it can be normal that ipcs doesn't list it anymore.
However, even on systems that don't have Apache running (like my simple RH8 box), ipcs -m still lists a bunch of stuff from other programs. The fact that your ipcs doesn't indicate anything at all, may point to a different problem, not specific for Apache, but for all processes who use shared memory.
A few questions:
-Can you try an ls -l of /var/run and /var/run/apache?
-Did you recently change anything to your system configuration, such as updates of the C libraries, etc?
-Are you absolutely sure that you ran the ipcs command under the root user?
-Can you please look at the other system logs in /var/log. Maybe there's an indication of a larger problem.
-What did fsck report back to you? And what did it fix, in order for your login to succeed?
Finally, I've read on a site that you could take a look at some pseudo-files in /proc, such as /proc/self/maps, but they're probably hard to understand.