Well it's very easy to test, so I'm pretty sure !
Use the CRM sample app, display a Customer detail form and then press the next icon (top right).
In IE7, the form stays steady all the time when data changes
in FF3, the form is redrawn each time after the 1st attribute (Number)
in Opera 9.63, the form stays steady or is redrawn up and then...
I know the difficulties to have the same behavior accross different browsers but one of the main objectives to AJAX technology is avoiding frame redrawn, isn't it ?