I think that was fixed in PT2.3D. Detron & Duff did an A1200 keyboard fix in that version. Remember that PT2.3B to PT2.3D were hacks by D&D, while PT2.3A was the last version by Peter 'Crayon' Hanning.
Try PT2.3E out and see if it works or not, or else I might look into it one day. I kind of need an A1200 first though, because the numpad mapping is weird in WinUAE.
Also a small correction: There were never 32 samples. 31 is the correct number. :-)