WebSignup not working

OS: Linux Server
Original Installation Version: 1.0.0

I attempted to use the following code in a new resource: [[WebSignup? &tpl=`FormSignup` &groups=`members`]]

While the right form came up, the form did not behave as expected. I could pretty much enter any data and the only thing that would change is the captcha image.

TESTING:
I couldn’t duplicate the environment exactly unfortunately but I went for it and installed Version 1.0.4 onto my laptop running Windows XP.

The identical code ran perfectly. I got error messages when the password was too short; and it created a user when I entered all the required data.


ROUND 2:
We decided to upgrade to 1.0.4 on the Linux server.
Nothing changed. I can enter the required data, or I can enter intentionally wrong information and no users are created or error messages are displayed.

Any ideas?

It needs to be uncached [!WebSignup? &tpl=`FormSignup` &groups=`members`!]; note the [!...!] tags.