Whats happening:- In main browser window, click on and icon which opens a popup window which contains an IFRAME. <BR><BR>Problem:- On certain PC's the popup locks. It then brings up a timout message (cant be sure but I think its from IIS). Click on that and the page displays as normal. From that point the window opens as normally until you log off. Any ideas? Browser versions, build and security look the same. The only difference seems to be that Interdev isnt installed.