Straight from the help file:

Added Professional Frequency Conversion code, this is an option in dMC's Configuration program (Release 9 and above),
Added own Stereo >> Mono conversion code to stop clipping,
8KHz, 12KHz and 16KHz frequency encoding options added,
Bug Fix - Ogg would crash when initializing for CBR or ABR with any frequency except 44100,
Bug Fix - Correct ID tag of TrackNumber now written for Track Numbers (was previously Track). NB this codec is still compatible with the old way of doing it as well.