I have tens of thousands of .mp3 files (and a half dozen other formats, my own rips are .ogg). I may try this out to see what happens. If you're still looking for help, I'd be willing to report and/or analyze results. The collection has been pieced together from other music collectors so has a wide variety of encoders and sources. I find many files are just bad in lots of different ways.
Thanks for the offer! Sure, help is always welcome. I think I should mention that in version 1.0 only serious bugs get fixed. I'm not sure when I'll start working on 1.1, but it should be this spring. Only after that new features, improvements, and minor bugs will be addressed (but we can talk about them sooner).
So please let me know if you find any issues with MP3 Diags. Also, feel free to ask questions about how the program works. (Reading the documentation would also be a good idea.)