So there are a couple submissions this afternoon that open up continuous print prompts. With a bit of dickering around I've found a really easy way to close it down without having to close your browser. I've done this myself on the first one, so I know it works in Windows running Firefox; if the operating system you're running has a comparable program, and if your browser works the same way, hopefully it will work for you too.
If it happens, hit Ctrl-Alt-Del to open up Task Manager and go to the Processes tab. Somewhere in the list will be plugin-container.exe; this is where your flash files run. End all instances of it until the print prompt goes away, then go and refresh any pages that were running something in Flash.
That's it; you have escaped the print-script. Hope this helps.