I'd say to double-check your config file and make sure the v is a lowercase v and not an uppercase V.
For me, when I used V (uppercase), it did nothing. Otherwise, v (lowercase) worked fine.
Granted, this was all on a PC monitor, but still...can't hurt to double-check.
Here is the command I ran at the prompt:
c:\emu\atari\z26> z26 -v18 combat