I found this post that guided me in the right direction:
Eclipse just crashed so I’m going to file a bug now…
I was getting the following error mentioned in the above post:
org.eclipse.swt.SWTError: XPCOM error -2147467262Accompanying the error was another error "Widget closed too soon!", which turned out to be related to the Welcome screen, which was being displayed since I had a fresh installation.
The bug post for this issue had a couple of suggestions.
First, since I am using Firefox 3, I tried moved /usr/lib/xulrunner-1.9b5 as a few kind people suggested. Ganyemede came up just fine, but Firefox would no longer work.
An alternative workaround mentioned first creating your workspace with Eclipse 3.x, closing the Welcome screen, and the running Ganyemede. I installed Eurpoa 3.3.2, restored xulrunner-1.9b5, ran Eurpoa, and then was able to bring Firefox and Ganyemede up with no problems.