Btw, you're running a very old distro, usually the .1 releases of RH fix a lot. I hope you kept up to date. Also you're running a 2.2.16 kernel. 2.2.18 should be the minimum wrt security fixes, 2.2.20 even better. Don't forget new kernel releases often have performance fixes as well.
If you're running "ps" try running "/bin/ps axfhwwwS -eo %C -eo uid,gid,pid,pri,args". This will give you per-process raw CPU time, including child processes, the uid/gid a process runs as as well as the process ID, priority and full commandline. I would recommend running atop and/or atsar. Atop is just a "better" top, and atsar is the Linux Sar equivalent. With kernel 2.4x you can use kernel profiling (LILO append line "profile=2") and then you can use "kerneltop" to see where the kernel spends most of its time in. Dunno if this works on 2.2x, I doubt it.