Was working on an flex based User Interface -SV team reported an issue that Till the time user has not filled all of the “Valid” details on the screen, the submit button remains should remain disabled.
I had purposely avoided this for following reasons

• There is in field hint and tip available for each of input field to assist user
• If users submit, there will be client side validation and any way wrong information cannot be submitted. Error can be more informative
• Displaying error message as user types, this can be irritating
• Why unnecessarily waste CPU cycle capturing keyboard events (Not a great point, but for listing sake ..)?

So a conflict between SV and Dev team –nothing unusual 🙂
Usability team was called in –and they mandated the SV objection, saying this has been done in some other products so I must comply…
Since it was more of my preference to avoid validation on key press, I gave in but would like to know how others think about this.