After some more tests, it seems that learned commands are also connected to the odd-even pair of button numbers.
Also I was unable to use numbers 1-6.

Jason, Yes I did, but I must confess I didn't really
looked at it (yet).
I also found out (but you probably already know) that text in table BUTTONTEXTTB will only show on the remote
iff the bx1 and by1 are exactly the same as corresponding fields x1 and y1 in BUTTONTB.
(yes I found out the hard way, changing x and y in
BUTTONTB to align my buttons ==> no more texts on remote (in PC software they did show !!!).