Look here =) http://java.sun.com/j2se/1.5.0/download.jsp
I don't think it's anything to do with a defrag or hard disk usage, Adobe PS CS2 runs fast on my computer even with LimeWire running at the same time =P
It's very strange...
Just in case I will run a few scans tonight, but I run a pretty healthy computer. Anyway, if you check out the Update 5 let me know how it goes. Thanks =)