[CentOS] Hlp with server load

I have a system that is running into problems with high load, however, 
even when I shut down everything that could be loading the system, the 
load continues to rise. I can't see anything that is causing the load. 
Any ideas?

08:36:06  up 1 day, 10:57,  3 users,  load average: 19.98, 19.30, 17.29
90 processes: 75 sleeping, 2 running, 13 zombie, 0 stopped
CPU states:  cpu    user    nice  system    irq  softirq  iowait    idle
           total    0.1%    0.0%    0.0%   0.1%     0.0%    0.0%   99.6%
Mem:   511916k av,  317756k used,  194160k free,       0k shrd,   35040k 
buff
                    208896k actv,   67280k in_d,   10488k in_c
Swap: 2048276k av,    5872k used, 2042404k free                  172064k 
cached

-- 
Chris Mason