Actually, to be honest... The comment should be 28 character long (regarding to the information) and a Chr$(0) to separate the comment with the track (those would be the 29 characters)

Or, in other words... you were pretty close hipopony66. They're saving the comments in 28 characters, and takes 2 for the track... but one of them is the chr(0) to separate both fields.

Check this site, if anyone wants more information: http://www.id3.org/id3v1.html