ZITAT(CopyTagger @ Jul 27 2011, 22:20)

... I have ...V2.4 tags. Is this the cause of the problem? How can I change them to V2.3?
Yes. W7 does not support V2.4 properly.
Have a look at Extras>Options>Mpeg.
For "write" set the radio button to "ID3V2.3 UTF-16".
Then filter for the Version 2.4 tags,
select all the files (Ctrl-A) - I hope there are not too many ...
right-click on the selected list
select "Cut tag" - this may take a while
immediately afterwards right click again and select "Paste tags" - this may take a while again.
If there are a lot of files, limit the selection to a decently sized chunks as a program failure after cutting the tags would lead to a loss of tag data for the files...
It is surgery on the open heart ;-)
So having backups is generally a good idea.
After pasting the tag version should be V2.3
I think iTunes also has a function to convert tag versions. But I can't say anything about the reliability of that function.