Hey Zed, send some of those drugs our way! No worries ... always fun to track these things down.
So, let's do some tracking on what I'm talking about:
1) Let's test ... here's how we play the game. Install the latest Firefox and Tab Mix.
2) In the options for Tab Mix, the javascript popup setting defaults to "no additional settings" ... leave it like that, or set it there if you've changed it.
3) Go to this page
http://www.pcmcomputing.com/lightscribe.htm ... you'll see two images, the bottom one, when clicked on, will display a larger image.
4) Click on the image to see a larger image, that will display it in a tab in the browser, now close it ...... Firefox crashes.
5) Start Firefox back up and go back to the JS popup setting, set to "allow resized popups in new window", and all is good.
Let's see if it dies for anyone else ... crashes for me.