I just noticed this post: http://goo.gl/tD8PRk. I'll check, but it may take care of my wav file issue.
Update: Using Audacity, I changed the settings to 16 bit PCM and exported the file as 16 bit PCM (see save settings pic); however, Audacity opens that audio file as 32-bit float (see open settings pic). I have attached the wav file, which does work for me in DirectRT, but I am wondering if this is why some of my files are not playing properly (they may actually be 32 bit float).