XP Pro: 90% of applications go into 'not responding' state

Hi all,

I am baffled by this. Every so often, around 2-3 times a day about
90% of the running applications go into a 'not responding' state but
the PC is not hung. I can still start Task Manager and launch new
applications (although they soon hang after launch). If you wait 5-10
minutes then everything jumps back into life - I just don't know where
to start troubleshooting.

Is there a application that can check what these processes are being
blocked on or give me some further help on this issue.

My system is an AMD 64 (K8NS Pro Motherboard) with 1GB of RAM and RAID
1 (mirrored pair).

Please help!!!

Thanks in advance,

Jason