Hallo,
I got the same problem > using w7 and some of my id3 tags are not shown in w7 explorer.
@cqwaters:
mp3val didn't work for me
I scanned 2 examples > both were ok > but still no id3 tags in w7 explorer
@Vjeetn:
Wikipedia says w7 can't handle id3v2.4
you said that you use id3v2.3
and so do I, at least I thought I would
I took some examples and let foobar override the id3v2.3
et voila the tags are visible again
Long time since I've been here 
Still no visible tags in Win 7 Win Explorer 
Thanks for the tips but none seem to work for me.
I just tried with foobar to override to v2.3 but still no luck.
I do assume you mean the program foobar2000, right?
I installed it, added an mp3, right clicked mp3 > Tagging > MP3 tag types... Then marked "override ID3v2 revision" and played around by (de)selecting all the options there but still no luck.
Unless I did something wrong and you can tell me exactly what to do/where to look.
Or if someone with same problem knows a solution, I'd be happy to hear 
Thx again.
Could you check in MP3tag ...
.... what kind of Tag versions are in the files. For this purpose create a column (unless it is already there) with the contents for value
%_tag_read%[ (%_tag%)]
.... if you found a 2.4 file set the options > Tags > Mpeg to ID3v2.3 UTF-16 for write
and then cut and paste the tag of the v3v2.4 file.
Check again in mp3tag which tag version is now present in the file.
If it says ID3v2.3 then check in Explorer what it thinks of the file.
If this still does not behave properly, then check it with mp3val.
And if all that has not helped a bit, I am at my wits end.
Sorry for replying to such an old post but I just wanted to add that it was in fact a problem with my Windows.
I've never discovered the real problem but after doing a Windows reinstall the problem disappeared.
I assume I had some corrupted files (probably DLL's) back then.