Sound font (sf2) crashing GarageBand

I found a great sounding acoustic chorded guitar sound font from JensenSamples.com, and installed their demo. But, it crashes GB as soon as I close out of the DLSMusicDevice window. I can play the demo in that window, but can't get it stable enough to work with it.

I know that sometimes demos don't work quite the same way as the full versions of products. Could this be a demo related issue? While on the subject, I'm looking for a chorded acoustic guitar sound font - any recommendations known to work well in GarageBand?

P.S. I'm running Mountain Lion (a very recent fresh OS install) , GarageBand ver6.0.5 on a iMac I5 quad core, 8GB ram.