I've been using computer sequencers for a while, with step time entry only,
but I recently tried playing notes in with a midi keyboard for the first
time (yes really). It worked fine for a while (maybe an hour or so), then
strange things started to happen.
It seems as if the midi messages are misfiring somehow. I either get notes
not appearing, not switching off (sustaining), or random low notes
appearing. These always seem to be bottom C (5 octaves below middle C) - no
matter what note I hit.

My equipment is as follows: Win2K, 736 chip, 256 RAM, SBLive card with newly
installed kX project drivers, Sibelius 1.4 notation software, Yamaha YPP-50
keyboard. I've tried using a different keyboard (Yamaha P-90) or recording
into Cakewalk, and the same thing happens.
I don't have another midi cable to test if it's that.

Anyone recognise this phenomenon?

JonR