HP Performance problem

I have not gotten much help from Informix or HP on this problem so I hope somebody out there can point me in the right direction. We have recently gone live on our production system and have started to run into a severe CPU bottleneck that is killing performance. We are running informix 7.12UC1 with about 25-30 users. The hardware is an HP9000 K200, 2-CPU's, 512 meg memory. When I run glance while the users are active the cpu usage is between 50-90 pct but will go to 100 percent for 5-10 min at a time. All other parameters appear to be reasonable it's only the cpu parameter that looks out of wack. When I look at the status of the processes it shows the oninit processes stopped on semaphores. If I drill down further and look at the wait states for the oninit processes I find that the process has been stopped waiting on semaphores for 90% of the interval and actual cpu usage is 10% of the interval. I'm treating this symptom as the cause of the CPU bottleneck but then again it could be the way the oninit process normally looks. I'm just using a S.W.A.G. to get to this point. Assuming it's a semaphore issue, here are the current kernel parameters: semaem 16384 semmap 512 semmni 4096 semmns 4096 semmnu 64 semume 32 semvmx 32767 Thanks in advance for any information.