None that I'm aware of.
Is the problem isolated to one IE9 machine?
Does it work on other machines or with other browsers?
What exactly do you see in the browser?
Here are some things you can try.
1) Make sure you are using the correct URL
2) Make sure your java security settings allows untrusted code.
3) Make sure your browser security policy isn't blocking cookies or code.
If possible past the relivant data from the server.log from the MWR server, and the text in the java console from the client.