First, a couple suggestions:
1. When asking a new and potentially unrelated question, it's a good idea to start a new
thread.
2. Use code tags for your code.
Back to your code: here's a hint. When trying to understand what's wrong with code, break it into smaller pieces. Your code have two parts: one half is listening to a combo box, and the other half is doing something in a table renderer. This two halfs are quite independent.
Test each in isolation. For example, your item listener is doing a case analysis on e.toString() -- why not print this
string out to see if it is what you are expecting it to be:
System.out.println(e.toString());