Try the tips here.
Reduce the drag caused by LW

The Java version that you'll link to from that post is now Java 6 update 2. Some people have had problems with that Java version, so it's up to you if you want to try that one or not. I'm using it & it's fine for me.

This older version of Java has worked better for a lot of people. Download
the JRE offline installer & remove your current Java before you install this one.
Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 11