Referencing a class in a jar results in "No document could be created".

Hi - complete newbie at XCode.

Trying to get a simple Cocoa-Java Document based Application going. Hello World, as it were.

All is good - app launches. I then add a jar file to the project, and then in the windowControllerDidLoadNib method (MyDocument.java), reference a really dumb class in that jar:

NullTimer timer = new NullTimer();

If I comment this code out, all works. If I leave this in, it compiles up, but when I run, I get a dialog stating: "No document could be created". The console:

[Session started at 2006-09-07 23:09:08 -0400.]
2006-09-07 23:09:09.903 cocoa[2911] The DocumentType type doesn't map to any NSDocumentClass.

I wrapped the call in a try/catch(Throwable) block, and no dice.

Stymied on something I thought would be simple.

Missing something pretty major - can anyone help me? I'm stumped.

Thanks.

parki...