[CentOS] Corrupted RPM DB can't be rebuilt.

Alle,

I have a major problem. I'm running CentOS 5.5 on some rather old hardware (Dual Celeron 500MHz with 768MB of memory). Sometime in the last week, the DB became corrupted (I noticed when yum update would hang). I've tried running rpm --rebuild with both the 2.6.18-194.17.4 and 2.6.18-194.26.1 kernels and get a segmentation fault each time. Consequently, I'm pretty much stuck and cannot do any update. Also, the machine has a tendency to hang any time operations are done. I've disabled some of the cronjobs that do this, but this is no way to operate. I would appreciate any input on where to go from here to try and rectify the problem.

Best Regards, Camron