Paladin2 has an on-the-fritz keypad or something. He explained it the other day.
I'm going to take a wild guess and say his "o" key is stuck...
There's solutions available other than using the zero... you could cut and paste the "o" from somewhere and use it... you could use Charmap... replace it with a hyphen, s-rt -f like this... r, my favrite, simply leave it ut altgether, peple will understand what yu mean.