That's right Zev,
ID3V2 COMM tags are not Comment fields. They are rather generic fields that can contains any data.
In this case the real (MC specifics) tag names that you see are "Tool Name" and "Tool Version" wih simply tell with which version of MC the tag was created. This can be quite useful, in particular when debugging a taggin problem. The real comment field is COMM(Comments).
as an example, here is the format info of an MPC file with APE tags. You can see again the "Tool Name" and "Tool version" tags under their own names.
MPC StreamVersion 7.0
Standard
168 kbps, VBR
44.1 khz, Mid/Side Stereo
10491 Frames, 274 Seconds
Tag: APE Tag 2.00 (588 bytes)
Track: 16
Year: 1972
Genre: Rock
Peak Level: 0,99997
Tool Version: 9.1.247
Artist: Rolling Stones
Tool Name: Media Center
Media Jukebox: BPM: 103
Media Jukebox: Rating: 3
Title: Stop Breaking Down
Media Jukebox: Intensity: 5
Album: Exile On Main Street
Media Jukebox: Cmagic SRC: CD
Replay Gain (radio): -9,53454
Media Jukebox: Cmagic OWN: CEA
Media Jukebox: Cmagic PRF: Male
Media Jukebox: Cmagic ENC: standard
Media Jukebox: Cmagic ATY: Original
Hope it helps you,
Bonne journée Y , portes toi bien et bonjour chez toi.
Christian