I also have had a similar experience, and has submitted it to bugs@empeg. I first thought this was a ID3v2 tag problem, but I now am pretty sure it is a emplode/player software limitation in the way the properties dialog accepts information. What I have found is that this problem is not limited to the comment field. I have been able to reperform this error at will. Just enter enough information in the property dialog fields and resync. You will find that at some point, when a certain limit on the amount of informaiton is exceeded, an already uploaded file will disappear in emplode/playlist on the empeg. However, it is still residing on the disc. You get a playlist icon with a red arrow.

/jhr

Mark 1 #317 - 20GB blue
Mark 2 #080000217 - 18 GB amber