UBB.Developers Forums Community Development Programming MySQL and Server Configuration Big MySQL problem

I have tried to install MySQL 4.0.16 over my 3.23.58 install. The server is a Dual Xeon 2.4 with 1GB ecc regged ddr and 2 x 18,3GB SCSI harddisks, runninh win2k, IIS5.0, AcxtivePerl 5 and php 4.3.
I followed all instructions for upgrade; Shutdown and remove the mysql service and installed 4.0.16.
Since I have installed 4.0.16 I have big problems.
At inconsequent times the MySQL server becomes really slow.
What I see in the MySQL control center you can see in the attachment.
The server seems to hang on the copy to temp table. When I kill that process it works again but otherwise I can take up to 1 minute before it reponds again.
Does anyone know what might have caused this and how to solve it?
We have about 200 - 350 people visiting the boards annd I get a lot of complaints about the long waiting times.
Sometimes it works fine for an hour, but then it starts again without any obvious reason.
I tried installing 3.23.58 again, but still the same problem.

Thanks for your help,

Ron.