MIDI Recording into Divisi problem

If you try to MIDI Record into a Divisi staff, you must go into Note Entry before pressing Record. If you just select a rest/note and press Record, then the new notes go into the Top divisi Staff, regardless of which stave you selected, over-writing what was there before.

I presume this is because all Divisi staves are on the same channel but display as different coloured voices, so the procedure is the same as for voices within one stave.

Yes, you need to specify the specific staff into which you want to record by way of the caret.