I've been trying to use the "required" validator on a select which options may be updated using Ajax. When the options are not updated, everything is ok and the "required" validator do its job. But when the options are updated using an Ajax call, the value is correctly updated but the "required" exception is fired and the form is reloaded with the required error message ... Looking at the Required validator code, the check is done on a not null and not blank value. So it should behave the same way, not regarding the content of the options ...
I haven't enough skills on Tapestry internal behavior to track down this behavior any futher. So i would be glad to get any clue ... Stephane