I found a few links that might explain what you are seeing:

Thread from spug.net
Palm KB article on the error

They are basically saying that any software running in the background (like IR keyboard drivers) could interfere with opening the IrDA library that I use to beam in Palantir. One way you could test this is by attempting to beam anything else (like a Contact or a Note) from the stock applications. If you still get the error try to track down any other hack/driver that might have the IrDA port locked up.