Cannot add Project Roles in Role Based Strategy Plug-In

In the "Manage and Assign Roles" screen. I cannot add project roles. I can populate the "Role to add" and "Pattern" fields, but nothing happens when I click on the Add button.I've tried various strings for Role and Pattern.

The plug in is not terribly useful without this functionality.

I can add Global Roles.

I was able to get this to work on Windows XP, but HP-UX is our production environment.

(I saw this issue was mentioned on the plug in page and the maintainer as to have the issue recorded here. I couldn't find any such issue, so I'm entering here. My apologies if this is a duplicate.)