I have been facing a issue with Radpopup window is...,if i open the radpopup 1st time, then page load of radpoup is executing but when open radpopup 2nd time, then page load of radpoup is not executing. please let us know the best solution to achieve this.
I tried the same and it happened for me even if I set the DestroyOnClose property of Windowto "True". So one work-around is invoking an ajaxRequest() from client side pageLoad() function and executing your code in Ajax_Request server event rather than in PageLoad.