Extra MIDI note down event occasionally being received

I've an unusual problem, sometimes during play Pianoteq is sounding an additional E above middle C note, which I did not play. It happens for just that E note, and it happens independently of what I'm playing, sometimes when that specific note was recently played and sometimes when it has not been played at all.

I've checked the MIDI events and the extra event comes in the middle of a bunch of pedal events, and it has the same velocity of the pedal event at the time:

ch1  Controller 64  value:78 (pedal)
19.434 ch5  Controller 64  value:78 (pedal)
19.444 ch3  Controller 64  value:78 (pedal)
19.444 ch1  Controller 64  value:71 (pedal)
19.444 ch5  Controller 64  value:71 (pedal)
19.444 ch3  Controller 64  value:71 (pedal)
19.444 ch1  Controller 64  value:65 (pedal)
19.444 ch5  Controller 64  value:65 (pedal)
19.444 ch3  Controller 64  value:65 (pedal)
19.444 ch1  Controller 64  value:59 (pedal)
19.444 ch1  Note 046 On (A#1) veloc: 67 (played)
19.454 ch1  Note 064 On (E3) veloc: 59 ( *** EXTRA EVENT ***)
19.454 ch3  Controller 64  value:59 (pedal)
19.454 ch1  Controller 64  value:48 (pedal)
19.454 ch5  Controller 64  value:48 (pedal)
19.454 ch3  Controller 64  value:48 (pedal).
... more pedal events ...
19.596 ch1  Note 046 Off (A#1) veloc: 96 (played note up)
...

The pedal event for ch 5 veloc 59 is missing - it would seem the Note On event is being sent instead?

I suspect the problem lies with the keyboard (Roland HP203). The no note-off event means that it keeps playing as long as it can or until I physically press the note again.

This only very rarely occurs - sometimes as little as once a month, although it happened twice this morning in a 5 minute period.

Any ideas anybody?