FIX FOUND for iPod classic refusing to play mp3s

Question

I have several albums on my iPod that I've ripped myself from my CDs (using EAC+Lame to rip, foobar2k to calculate replay gain and mp3tag to clean up tags and convert RPG to iTunes soundcheck). These files play fine on iTunes and any other program, and played fine on my 5.5G iPod. But they wouldn't play on my new iPod classic. Resetting or restoring the iPod had no effect.
After examining the files with a hex editor, I found that these files actually had TWO ID3v2 tags, one after the other at the start of the file. I used the hex editor to strip out the second superfluous ID3 tag and a load of null padding after it, making sure that I deleted an even number of bytes so that the word alignment wasn't affected.
The files now play fine.
It seems that the previous iPod firmware was robust enough to ignore the extra ID3v2 tag, but the current version gets confused. The root cause, though, clearly lies with the tagging programs I used rather than Apple, and with a poor definition of the ID3 standard in general.
I've been looking around for an automated solution that will scan my entire library for erroneous tags. I'm currently testing ID3Cleanup from http://www.musicip.com/freetools.jsp, which seems as if it removes the superfluous tag and padding correctly.

Answer 1

Do this on a COPY of your mp3 files to test first.
If your MP3 has artwork embedded in it, the artwork will be stripped out.
Go to http://www.musicip.com/freetools.jsp
and download ID3Cleanup (available in Windows, Unix and Mac versions) into the folder with your files.
Open a command shell (terminal) and change directory to the folder with your test files then type in
ID3Cleanup -compact .
(note the dot at the end)
Sync the files to your iPod and see if they play. If not, then you may have a different problem.