I installed that extension in FF 3.7 + Firebug 1.55a22pre. I opened
gmail and reloaded the page. After that was complete, I opened a new
tab and closed the gmail tab.
I got a lot of pop up alerts. Some were empty, some had stuff. Some
with stuff listed "window" as leaked; some listed elements.
Now what? I did not see anything that helped me find a problem.
jjb