[plt-scheme] Appalling performance of DrScheme on Windows

I am running DrScheme on Windows XP and I regularly experience abysmal 
response time running DrScheme.

Usually its starts off ok but the longer its left running the worse the 
response time gets (especially if you leave a session idle for a long time). 
It is not uncommon for me to manage only 4 interactions in an hour because 
DrScheme just hangs for ages before it will accept input.

Previously I had the same problem running under Win2k. I thought it would go 
away when I bought a new machine last year runnnig windows XP but its just 
as bad.

It is pretty much impossible to use the environment with this sort of 
response time.