Open Moz. Open a new window. Click the spinner in the new window. The -original- window will go to mozilla.org instead of the new window. This happens about 75% of the time. The other 25% of the time, the new window goes to mozilla.org as expected. But if you then close this window, open a new window again, and click its spinner, 100% of the time the original window incorrectly goes to mozilla.org instead of the new one. At least that's been my experience.
What build are you testing?
Sorry, i thought that would be automatically included in the bug submission. I'm not going to be able to give you the exact release ID until Monday, but it was the current Linux nightly build as of this afternoon.
Is this still a problem in current builds?
I can't reproduce the problem anymore with current builds.