Hello, I have a problem with one of my servers:

Kernel and CPU Linux 2.6.18-194.32.1.el5 on x86_64
Processor information AMD Opteron(tm) Processor 6128, 8 cores
CPU load averages 3.22 (1 min) 3.27 (5 mins) 3.15 (15 mins)
CPU usage 20% user, 2% kernel, 0% IO, 77% idle
Real memory 3.86 GB total, 1.85 GB used
Virtual memory 5.81 GB total, 152 kB used
Local disk space 445.39 GB total, 42.20 GB used

I have complains from my clients that their gameservers are blocking for 3-4 seconds.I use this server only for gamehosting and nothing else.What could it be.First I thought it is the client's game mode, but I get several complains.What should I do and what should I check for?Thanks.