While using RadUpload control on RadGrid Edit Popup, and clicking Select button of RadUpload control, it's not working for FireFix 4+ (OpenFileDialog is not shown) but it works properly for Safari and Chrome. I using that the following Telerik Version 2009.3.1103.35.
The following code represents EditFormSettings
<EditFormSettings EditFormType="WebUserControl" UserControlName="StudentDependent.ascx" InsertCaption="Add new dependent">
<PopUpSettings Modal="true" ScrollBars="Auto" />
</EditFormSettings>