Can I use ASP.NET validation controls to enforce additional validations for data entered into a WebpercentEditor control.

I created a test page with ASP.NET data type validation (using Range Validator) on a WebPercentEditor control. Validation works just fine as long as there is no postback involved. But after a postback, if I submit the form the validation fails. If I tab in and tab out of the percent editor control, I don't see the same validation error again. Ami I missing something?

-Ramesh