Can you try running a simple command like /usr/bin/date and see how and what it returns?

I'm guessing that your shell script isn't working because of environment differences. Remember, when you remotely run a command via ssh, you don't get the same environment as you get after logging in normally.

One thing I like to do is remotely run the set command under ksh. This will dump the environment of your remote commands so you can see what you have v.s. what you need.

-Craig