Hi,
We have seen this error once or twice before, but the cause has mostly been an odd configuration change, such as placing jrebel.jar into tomcat libs.
Can you send the jrebel.log after receiving this error? The easiest way is from eclipse Help -> JRebel -> Submit a support ticket.
Then make sure jrebel.log is attached. Please also include the link to this forum post.
From the log we should be able to see what is causing the cyclic hierarchy.