Songbird does not transfer music to MTP, only transfers folders

Songbird is not transferring media to my MTP device (Sony Walkman NWZ-A728) even though it had done so previously. I have not had to sync to it for several months, at which point I think I was using SB 1.1, but it worked perfectly before. Songbird still recognizes my media player and when I try to transfer songs - both syncing and manually transferring - it only adds folders and playlists. SB still recognizes all of the specs and the space remaining.

I also receive the "Media Management error" when editing metadata which I read is being fixed, so I was waiting for 1.4 to come out to see if this is related to that or another fix. Currently I use SB 1.2 and have Windows Vista, and all of the music I try to transfer is in recognized formats (mp3 or m4a).