In 3.7.0 I select all the fields other than the main fields I want info in. I then right click and chose delete. This clears out all the extra garbage that may be tagged in the files. However on the ID3 Edit tag when I do this it does not clear out the info in the Comment or the Not Supported List fields which it does with no issue in 3.6.
EDIT: Downgraded to the copy of 3.6 I had saved. Tested again on those same files and they cleared the info in those fields with no issue. Appears to be related to only 3.7. Saved a copy of the files before I updated them with 3.6 so I can reproduce this.
Could have 3.7 reintroduced a similar bug that was in 3.5 when it first got released http://www.jthink.net/jaikozforum/posts/list/1302.page ?