Yeah, there's something wrong with that. I've loaded it into Goldwave, which I know supports 24-bit WAV since I've used it many times with a Fostex FR-2 compactflash recorder, and the 24-bit version is covered in hash. Same in Premiere Pro.
I've done quite a bit of programming with WAVE files but on examining the internal structure there doesn't really seem to be that much wrong with it; the only slight oddity is that the header specifies a two-channel left/right mapping for what is a mono file, but I can't see that this would put much software off. Otherwise it just appears to be a perfectly normal modern wave file with 24-bit three-byte data in it. Nothing special at all.
I also tried a bit of byte reordering on the main data, because it's quite easy to make mistakes with WAVE formatting for 24-bit data, but (as I suspected) they haven't made such basic errors here.
I would therefore suspect that the problem is baked into the sample data itself and there may be a fault with the audio circuitry in your recorder, but I don't know for sure.