It is a bug| This is an issue we have discovered soon after having released the RTW. The ClientValidator, that substantially, is responsible for adding unobtrusive validation for controlling the number format, has been cleared because we prepared a custom
version of this validator. Unluckly we moved this task to another release without re-adding the old Validator.
In a short time (7-10 days) we will release an SP1 with the new custom version of the validator, that will allow the customization of the format error message (that is impossible with the actual Mvc 3 version), and another couple of bugs, plus an enhacement
of the TypedTextBox and TypedEditDisplay. In the meantime you can re-add it:
Sorry for the inconvenience!