ClassCastException when editing a pathway for the 2nd time

[martijn]

How to reproduce:

• Start firefox
• Go to a pathway page and click the edit button, for example WP1461
• close
• Click the edit button again.
• Observe an error message. Screenshot attached

This in firefox, using Ubuntu 10.04.

I have a feeling this has to do with static instances. See  http://www.jarvana.com/jarvana/view/com/jgoodies/forms/1.2.0/forms-1.2.0-javadoc.jar!/com/jgoodies/forms/layout/LayoutMap.html#getRoot%28%29

There is no stack trace in WikiPathways?.log. Restarting firefox is sufficient to reset the problem, to get me going for one more time. So the problem is really inside a single JVM, it has nothing to do with applet cache conflicts.