The behaviour seems to be erratic at best. Now that I'm testing it again with SQ5, playing one sound works fine, but then after trying to test a few others it starts freaking out and then none of the sounds will work. Given my previous experience with this version of SV there's no telling how far the glitches go or what triggers them, but it's not very reliable. I suppose one should simply export the sound you want first as soon as you load a new game after launching the program. It's the only way to be sure.