As of the latest update in Firefox browser (v2.0.0.2 or v1.5.0.10) r.a.d.controls might not behave as expected in some AJAX scenarios. Firefox rendering engine has been dramatically changed in this minor update and JavaScript code (which manages client-side behavior of r.a.d.controls) is now loaded later than in previous versions. As a result r.a.d.controls in specific AJAX scenarios might not be immediately updated and appear to be flickering. We are currently investigating a possible workaround for that limitation but we hope the Firefox team will release another patch to fix this. Nevertheless we will do our best to address the issue as soon as possible. Please, excuse us for the inconvenience.
This problem can also be seen with ASP.NET AJAX JavaScript code as described in this forum thread.
We will continue to provide updates on the problem.
Regards,
the telerik team