Weird, it seems like the sounds are not loading. Can you check in your options if the option "Stream sounds" is checked. If it is, uncheck it. I'll try to figure out the problem.
"Stream sounds" is not checked. It also doesn't seem to save that setting - when I set "Stream sounds" to checked, and then close Sound Show, it's unchecked again the next time I open it.
(the sounds files are mp3 and wav files, if that matters)