Reproducible BUG found!
Here were the circumstances:
I created a form yesterday and applied verification to each of the required fields. I also attempted to filter each field of what I thought were invalid characters.
After having done this I today added another form to the page, just above the one from yesterday. This new form had a single button and no input fields. It allowed me to capture a button click and redirect to a new page.
The client sent an email and complained that the fields on the form created yesterday were not allowing enough characters. He want to be able to enter commas, pound sign characters and the like. My first thought was to add in the allowable characters and realized that simply omitting the alphanumeric validation would achieve the same effect, so I did.
I clicked the FINISH button and went to test the validation. The form kept complaining that a field intended to hold a ZIP CODE was invalid. I was stunned so I started checking what could be causing this.
It was then that I discovered that each of the fields as described in the ONSUBMIT portion of the FORM tag had the very same field name. I tried nearly a dozen times to get it to produce the validation text correctly but it would not.
Finally I decided to remove the first form and re-enter the page and try to add the corrected validations again. This time it worked. I ended by pasting the newly created form back into its location and everything worked well.
SUMMARY: The bug appears to be associated with the presence of the second form. Not sure why but it was repeatable.