Unfortunately that doesn't seem to have helped. I reset my settings as well which also made no difference.
I usually have all of my files playing on shuffle, which amounts to about 4000 songs. I just tried having a one song playlist playing when I plugged the Clip+ in to the computer and I don't get the error so does this have something to do with the playlist being too large? Perhaps there is not enough space on my Clip+ drive for the file to save? I have about 600mb free on the drive with the rockbox data on, is that too little?
I've only encountered this problem since the last update (which I've only just installed), is it not being treated as a bug? There seem to be quite a few people with this problem.