mysql takes ages even when not actually used in my code

I'm having a problem that all my data is sent to the client and THEN it 
waits a few seconds, I can see my browser in a waiting state. This is a 
script that only has echo 'test'; in it, so no database action or anything.

When I remove mysqli from php.ini it works fine, but the moment I add it and 
restart my iis, the problem is there again.

I could really use some help here. I have mysql5.1, last version of php, 
this happens both on a very old windows2000 server machine and a windows2003 
server, not on my vistasp1 development pc.

robert