Clip+: mono ogg vorbis files skip?

[bk0]

Just got my clip+ today. It is running firmware 1.02.09A. I have an archive of ogg vorbis files encoded as 32kbps 22050 Hz mono. I loaded a few onto the player and they playback with a loud harsh 'clicky'/static noise overlaid on them making them unlistenable. They play fine on a 1G ipod nano running Rockbox.

As an experiment, I re-encoded a file as:

a) 64kbps* 44100 Hz mono - same problem
b) 64kbps 22050 Hz stereo - plays fine

[* dbpoweramp codec didn't seem to support original 32k bitrate]

So it seems the firmware has problems with mono ogg vorbis files. Anyone else experience this? This is a shame because playing these files was a big reason why I bought the player.