IntelliJ crashes running on Vista

I am using IntelliJ 6.0.4 with Java 1.5.0_10 on Vista Business edition. When I compile the classes in my project every now and then IntelliJ freezes while loading the classes. I then have to restart the computer to be able to work again. This happens approximately once per hours. Sometimes more often and sometimes more frequent. What should I do to resolve this? It is driving me insane...

Do you need more information?

Thanks!! /Tom