psscale: black lines to separate different colour intervals. (-S)

Hi,
why there is no saparated lines in this example
>psscale -Csst.cpt -D17.c/0c/10c/.5ch  -B4::/:"tCø":WSn
sst.cpt file:
#	cpt file created by: Alex
#COLOR_MODEL = RGB
0    0  255  255    4    0  255  255
4   17  245  238    8   17  245  238
8   51  225  204   12   51  225  204
12   85  204  170   16   85  204  170
16  119  184  136   20  119  184  136
20  153  164  102   24  153  164  102
24  187  143   68   28  187  143   68
28  221  123   34   32  221  123   34
32  255    0    0   34  255    0    0

Thanks

Alex Kukharsky

SRC Planeta