> 
> My experience is that Windows services and assorted background processes can
> grab system resources at inconvenient times.  I have an ATI video card I use for
> video capture, and I try to make sure nothing significant is running if I'm
> grabbing video, else it drops frames.
> 
> 
> See what task manager shows, and try shutting down everything non-essential
> (e.g. web servers, ant-virus, Outlook ...), then run the tests again.
> 
> 
> James

I should have said in my original post, that I already tried this.
I have also tried setting the thread to max priority.

thread = Thread.current
thread.priority=31  #max priority for Win32
Thread.critical = true