Running /etc/cron.daily/makewhatis.cron dumps core. "file core" says: "process `sort' killed by signal 11". My system has been installed with German locale.
We (Red Hat) should really try to resolve this before next release.
Are you able to do other large jobs, like compilings kernels (preferably 10 times or so in a row) without sig11? I've run this many times without such problems, and would highly suspect your hardware (overclocking or bad memory chip). I recommend try the adwise found at http://www.desy.de/unix/linux/memtest/ and http://www.bitwizard.nl/sig11/. Reopen if all of these tests succeed.
It's an otherwise very stable 440BX-based system that is *not* overclocked. Solid Pentium power. It has been compiling kernels for hours (with "make -j8") and ran Memtest-86 for more than 10 hours. So I guess, we're back in game... I tried to reproduce the bug on a minimal install but makewhatis does not seem to find enough man-pages to crash. My assumption is that German locale plus maybe a strange man-page could be the cause. If somebody at www.redhat.de has an "Everything"-install in German and could try to verify that? I'll try to reproduce the bug this weekend myself. PS: Yes, I have verified the MD5SUM's after download and checked every single RPM with "rpm -K".
The sort bug was fixed in textutils-2.0.11-6, after the wolverine release. You can test http://people.redhat.com/laroche/textutils* if you want to fix this. Please open a new bug if you can still make sort crash with some special locale settings.