When I write tag data to large batches of files, Mp3tag somehow manages to trick Explorer into thinking the songs are 00:00 in length and only writes the Artist tag, while erasing all of the rest. Oddly, this doesn't happen when I only write tags to one song or to a handful of songs (the most recent incident was with ~250 songs but it's happened to much larger batches).
This wouldn't be a huge problem, except Microsoft software has issues with it. I can't burn these songs to CDs, the playtime tracker on both the Zune software and the actual Zune itself don't work properly, etc. While I've learned to name Mp3s in a format that keeps all of the crucial information stored (%artist% - %album% - %title%.mp3), I would rather have it in tags and show up properly.
This has been going on for quite some time; I've looked around the forum and the rest of the Internet and can't seem to find anything that actually works - aside from reconverting the files, which wipes the rest of the tags (and takes a couple of hours). Mp3tag's a brilliant program and I love everything else about it, but I'm kinda obsessive about my music collection (hence my interest in Mp3tag) and I would like to be able to enjoy it without this issue.
Well, as far as I can tell, just Cutting and Saving has allowed Explorer to pick up the proper length. Still not sure why the problem was occurring to begin with, but at least I can fix it if/when it happens again. I'm probably just ignorant of some "feature" of my conversion software that adds all tags from the file's history to the converted song - especially since I had to Cut twice to get rid of a second set of tags that popped up, tags from a few years ago.
Not sure if this is related but there is a similar "bug" in Windows Explorer and WMP (and maybe Zune software?). These programs will prefer reading a Length field (TLEN) in the tag if one exists over the actual duration of the file. They quite rightly expect an numerical value in milliseconds in this field, but if the value is malformed e.g. "3:30" with a colon then the duration can be displayed as 00:00 in Explorer, and WMP has problems displaying the elapsed time.
Perhaps a malformed TLEN field is being written by your conversion program?
That's kinda what I was thinking, but the freshly converted files are always shown with the proper duration in Explorer, Zune, and Mp3tag; the problem only started occurring whenever I would use Mp3tag on a large batch of files. I haven't really tried to experiment with this at all, so the best guess I can give as to what makes a "large" batch is more than 8 mp3 files (but the real cutoff is probably much larger). Handling the same size batches in either Zune or Explorer didn't create any such problem, but Mp3tag is just better at it, aside from this one small thing.