Synthesizer is slow to respond and sometimes crashes.

So, I have 3 soundfonts loaded into the Synthesizer: the default, the new HQ one, and GeneralUser GS. I have 3 scores open, one of which is large, the other two are not. I go to the synthesizer and try to change the soundfont. Usually it is pretty slow, occasionally the Synthesizer crashes (NOT Musescore), and then just a minute ago I tried to do it twice and the whole Musescore program crashed. Then I uninstalled MDL to resolve a different issue and it stopped crashing, but the Synthesizer still works slow.
Any ideas? (And thanks for your patience; this is my third Issue tracker post in one day, after all.)