When there is a RadButton with configured ValidationGroup, the client-side ASP.NET validation on the page will not be executed, if there are validation controls, which use the same ValidationGroup. The unexpected behaviour is observed in FireFox and Opera.
When a RadButton with configured ValidationGroup is used on a master page its server-side event 'Click' is not raised in: -Internet Explorer and Chrome, but FireFox and Opera. -In all browsers when the master page contains a RadAjaxManager.