Webrat has selenium.jar included in it. If you turn on selenium mode
you should see a message that says the firefox home must be in your
path. This is the home directory for firefox 3 and the default for
selenium mode. If you are using a selenium grid there are more
settings and more things to check. I can help you guys out, but I
need to know if you are running against the grid or locally. I would
suggest getting it to run locally first.
Amos