For now, you need to allow pop-up windows on Gmail as a workaround. Here's how: While you have the compose window on the screen, click the padlock in the address bar. * If the pop-up permission is listed there as Block, try changing it to Allow. * If the pop-up permission is not listed there, click More Information to launch the Page Info dialog, then click Permissions in the top bar. Scroll down to "Open pop-up windows", uncheck the box for "Set default" then click Allow and close the dialog. Then try the paper clip again. Success? Unfortunately, that is "Google-wide" and not limited to mail, so... other pop-ups are possible that you've never noticed before. Google indicates on their forums that their working on fixing this, so you might check in a couple days whether you can block pop-ups on Google again.