If this is the header that musicmatch leaves out then the time remaining display in winamp will be incorrect.
Symptoms also include the bitrate display changing all the time..

I use MP3 tag studio to "repair" all of my vbr files and they work great on the empeg...(Check the release notes for a mention of how the wrong vbr headers can screw up fastforward and rewind)

Jazz
(List 112, Mk2 12 gig #40. Mk1 4 gig #30. Mk3 1.6 16v)