post your config, strip the passwords.
Are you certain there is a www service running on the machine you are trying to forward to? Did you enable all three forwards at the same time? If so, and www isn't working, then I expect it to be a www server issue.
If www was the last forward you enabled, did you try issuing a clear xlate after you did it (if you rebooted the pix after the change, this would be unnecessary though).
