Growl notifications not working

I use Spark on a Mac and Growl notifications haven’t been working for me for some time. I think they stopped when I upgraded my OS to Snow Leopard although I can’t be sure about that.

I’ve looked in the Spark preferences and I don’t see much about setting up notifications. Can anyone help? How do I get Growl to work with Spark?

PS - I’m using Spark 2.5.8 and Growl 1.2.1. My Growl prefs have Spark set up, so that’s not the problem.

I tried running Spark from the command line and I see some errors coming up. When I receive an IM, I get a NoClassDefFoundError for com.apple.cocoa.application.NSApplication. I think this class has been removed in Snow Leopard and this is causing the problem.

Any ideas for me?