MIDI keyboard won't input notes

Hi,
I'm using a Korg Keylab61 that is recognised in Musescore's I/O section and can be heard when I play through Musescore but will not input notes. Can you confirm how my I/O should be set? I've tried several different ways but to no effect. My interface is a MOTU 828Mk3 hybrid which is also recognised in the I/O settings of MuseScore and seems to play through properly but still no note input.
Thanks!
Paul