The "For during your break" games do not work.
A pop-up blocker is installed on your PC. It prevents the relevant window from opening. Please deactivate all pop-up blockers and try again. Please note that, apart from your browser, pop-up blockers are often installed in toolbars such as Google-Toolbar or Yahoo!-Toolbar, and also very often in "Personal Firewalls" such as, for instance, Norton Internet Security. You definitely have to deactivate all pop-up blockers before everything can work again.
If the window opens but no game appears, Flash is probably missing. You can download Flash here and install it.