I was incorrect in my last post. I decided to double check. Although, I am using Java 1.4.2 with Linux, it is actually 1.5.0 update 2 that is installed on my laptop. That is what I get for relying on my memory before. Specifically, the Add/Remove Programs list says it is J2SE Run Environment version 1.5 update 2. Also, it is a jre-1.5.0_2 folder beneath the Java subfolder in the Program Files folder.
Offhand, I cannot give specific advice. To me, it sounds like a file is corrupt or missing or maybe it is trying to use some files from one version and other files from another version. If it were me, I would try downloading and installing the latest JRE 1.5 version. If that did not work, I would try removing all Java versions, making sure there was no Java subfolder any more beneath Program Files, and then installing the latest JRE 1.5 version again. If that still did not work, if possible, I would try posting a message in the Java support forums similar to what you saw. I would include as much information about the environment as possible: Windows version, language, etc..
I wish I could offer more. Even being a computer professional, these things are often difficult for me as well. They do not think of all of the different possibilities of computer environments and varying degrees of experience.
Good luck. I hope you can get ZOOT working again.