Eclipse Installation Issue

I am running Ubuntu 11.04 for development, and I was going to use the Vaadin plugin for Eclipse, and I successfully installed that plugin, but when I attempt to create a new Vaadin Project, I get this error.

The selected wizard could not be started.
Plug-in "com.vaadin.integration.eclipse" was unable to instantiate class "com.vaadin.integration.eclipse.wizards.VaadinProjectWizard".

Is there any way to fix this?

This sounds similar to this thread

Which Eclipse version are you using?

The problem is not clear to me, but also try to update the Vaadin plug-in and WTP plug-ins to the latest versions if you haven’t done so already.