Unstable imported fonts in Garageband

In March 2008 "jenrou", working with GB3 and Mountain lion wrote: "I can download the sf2 files, and put them in the correct Banks folder, but when I open them up in GB I can't get them to play correctly: I can create a new instrument, (e.g. a wooden flute) test it out on the keyboard, fine, and pick it for a track. All's good. But if I stop the playback, and restart, suddenly that new instrument track is silent. After the soundfont file instruments go silent, I can re-open them, via the generator (DLSMusicService) and start the process over ... regardless of what I do I also can't export the file to iTunes with the new instrument tracks -- just the tracks with original GB instruments play without fault and get exported."

Now, 6 years later, I am having exactly the same problem with GB9 and Mavericks. I see others have lots of problems with their computer crashing with DLS server. That isn't happening with me, but I have a real struggle to get the DLS server to respond - it sees the fonts, but won't allow me to choose them. When it does, as with happened with jenrou and many others, they go silent after one play.

Ha Garageband not solved this problem in 6 years? Any tips?