Parola zone problem

Other Hardware Displays
5

Ok, I tried the following (in the original Parola_Zone_Display example, lines 133ff):

P.setZone(0, 0, 3);
P.setZone(1, 8, 11);
P.setZone(2, 16, 19);
P.setZone(3, 24, 27);

==> this works fine

P.setZone(0, 0, 6);
P.setZone(1, 8, 14);
P.setZone(2, 16, 22);
P.setZone(3, 24, 30);

==> this works fine, too

P.setZone(0, 0, 7);
P.setZone(1, 8, 15);
P.setZone(2, 16, 23);
P.setZone(3, 24, 30);

==> still working

but:

P.setZone(0, 0, 7);
P.setZone(1, 8, 15);
P.setZone(2, 16, 23);
P.setZone(3, 24, 31);

==> does not work at all

Platforms used were Arduino Nano, Uno and Mega; all with the same result.