Not sure what the issue is exactly. I noticed that some of your files would play (from a support email, e.g., g.wav, s.wav) but that others wouldn't. There were some minor differences between the files in terms of sampling rate I think, but that shouldn't make a difference. I opened up a couple of files that would not play in a freeware program called Audacity and chose the Export as WAV option. Audacity has the tendency to clean up any abnormalities in a sound file when exporting--even if you are exporting it to its current format.
Anyways, this seemed to work (at least on this computer). You can try it and see what I mean. When I first played the "crayons" sound file in DirectRT I got the "BEEP" you described. After opening and saving it in Audacity, it played fine (see attached). Can you check this file out on your machine and see if that helps?