-Ba -Bz works on Modern but screws on Classic

[joa-quim]

This works

gmt psbasemap -R0/6/0/6/0/6 -JX10c -JZ4c -p135/44 -Ba -Bz -png lixo1

this too, though with different defaults

psbasemap -R0/6/0/6/0/6 -JX10c -JZ4c -p135/44 -Ba -Bza -P > lixo2.ps

but this one with -Ba -Bz shows only a vertical bar

psbasemap -R0/6/0/6/0/6 -JX10c -JZ4c -p135/44 -Ba -Bz -P > lixo3.ps

Issue is that when parsing the -Bz the previous -Ba settings are wiped out.