(Filing as unconfirmed, since I haven't confirmed this myself. Based entirely on a comment on Slashdot.) Steps a to reproduce (based on http://news.slashdot.org/comments.pl?sid=3026683&cid=40880421 ): 1) When running Firefox n, set the Firefox update preference to "Check for updates, but let me choose whether to install them" 2) Wait for Firefox n+1.0 To be released and unthrottled. 3) Decline the update to Firefox n+1.0 when prompted 4) Wait for Firefox n+1.0.1 chemspill 5) Keep running and quitting Firefox until itself-updates to n+1.0.1 6) Look at the update log Actual results: The n+1.0.1 chemspill release got installed over version n without an opportunity to choose whether to install it despite the user setting. Expected results: Expected the "let me choose whether to install them" pref to mean what it says and give the user the opportunity to choose whether to install chemspills.