Greenhopper causes a hang

Using greenhopper seems to be causing all of my Jira installation to hang.

Steps to reproduce:

1. Select Agile | Planning board from the main menu
2. Click on "Unscheduled" in the right project list
   1. It seems to happen any time I click on a "Project" in the right column.

Note:
The spinning logo next to the "My Issues" check. This continues until my proxy server indicates that the connection has timed out (couple minutes).

Lengthy Details

After this, Jira is hung - will not shut down and will not accept connections. Connections are not rejected, but Jira does not respond. Specifically, if I try to connect a browser, it spins waiting for a response from Jira. If I kill the Jira process on the server (will not shut down gracefully at this point), the proxy server indicates immediately that the connection was terminated.

After bringing Jira back up, all my issues are present and Jira behaves as expected. Going back to Greenhopper and clicking on a task in the right pane will again cause it to hang up. Greenhopper seems to work OK as long as I don't click on any of the task boards.

I recently went through the Dragon's Quest for integration and successfully completed all steps. Due to memory constraints on the machine I am working with, I have turned off Fisheye and Bamboo until I can find another machine to install them on. This leaves me 1GB of free memory, so I know that system memory is not the issue.

Here is what I have running on the machine:

1. Crowd 2.0.3 (crowd directory) Stand Alone
2. Jira 4.0.2 War (Tomcat 6.0.24)
3. Greenhopper 4.3
4. Confluence 3.1.1 Stand Alone

Please help me identify what else may be useful in figuring out what is going on here.

Thanks!