I don't actually see the problem with Chrome. The popupchecker JavaScript function may return the 'wrong' result, but actually, the quiz works. When you click on the start quiz button, the pop-up actually appears, and you can take the quiz, because modern pop-up blockers are clever, and will allow a pop-up if you just clicked on something.
I think the problem is with Firefox, and similar, where the behaviour is the same as in Chrome. You click on the start attempt button, and the quiz opens in a popup. The only problem is that when you arrive at the quiz view page, you get a stupid alert telling you to turn off your pop-up blocker.
So I have just removed the pop-up blocker check. Since the quiz was the only user of the broken popupchecker function, I removed that function too.
I have tested on IE, Firefox, Chrome, Safari and Opera (all on Windows) and it all seems to work.
Except in Opera, which is nice to its users, and does not let you open obnoxious full-screen pop-ups. The quiz still works though, it just appears in a new tab.
By the way, the whole full-screen pop-up thing is a bit silly on a multi-monitor system such as the one I have here. It just opens full-screen on one of the monitors, so you can still get at other stuff. I really wish I could get rid of 'secure' mode, but Martin won't let me.
Anyway, I think my change is the best we can do for now.
Bug
Closed
Minor
I'll try to fix this before the release.