Error -2041: an invalid sample description was found in the movie (MOVIENAME.mp4) with Replay Media Catcher

I'm using Replay Media Catcher. I get this error on some of the .mp4 files at lynda.com. On some tutorials, about 1/3 capture perfectly, on others none will capture but give the same error, and on still other tutorials all of them capture just fine without exception. I have tried the suggestions posted by applian without success. I found one other user who was getting the same error at lynda.com. Oddly, (to me, anyway), I can convert the .mp4 files that won't open to .wmv and they will then work fine. Any help would be much appreciated.