Catalogue of Syncing Problems

[Stealthy]

Everything was fine up until a couple of days ago: I wanted to add a couple of songs onto a playlist - I connected my phone to my laptop, Winamp loaded up my device, I sent the relevant playlist and I ejected. Routine.

And when I went to listen to the playlist on my phone, the playlist was entirely absent and the new tunes, even though they appear on my SD and are playable from an explorer program, do not turn up anywhere within the app itself.

Even more perplexing is that there are 5 other playlists I didn't edit or sync and they are detected just fine.

Nothing I've tried solves this and what's more, after just now seeing if deleting the tracks and resyncing will work, Winamp is now telling me that a FLAC file - which it had been playing with no problem for months just a couple of days ago is no longer compatible and will no longer sync.

What exactly is going on?