According to a post on the Mozilla support forum, “Seeing links for [Firefox 9.0.1], why is it being released? Or is it a hoax?” Other discussions on the support forum’s threads included messages from users asking whether or not Mozilla actually updated the Firefox browser and if so, why?
Mozilla did not specify in the release notes of v9.0.1 why it needed to re-release the browser though developers did note that the update was prompted by crash reports, specifically for Mac users, though Windows and Linux users also experienced crashes. According to a statement from Alex Keybl, one of the engineering Project Managers on Mozilla’s Release Team, “We built Firefox 9.0.1 with bug 708572 backed out. We’ve pushed Firefox 9.0.1 for all platforms. Although, we think Windows is mostly unaffected, we still decided to move forward with Windows-v9.0.1.”
In order to rectify the problem, one that caused crashes whenever users ran certain add-on toolbars (like the one distributed by the Dallas Cowboys), the developers at Mozilla removed a patch that had been applied previously. The rush update that occurred on Wednesday was the second by Mozilla in the last 30 days. Mozilla shipped Firefox 8.0.1 back on November 21 to deal with a large number of crashes with Mac OS X. The crashes were eventually traced back to an Apple update of Java that occurred earlier in the month.
Anybody who upgraded to Firefox 9 in between the time of its release and the release of 9.0.1 can update to the new version by choosing “About Firefox” from the Firefox menu on the Mac or “About Firefox” from the Help menu under the Firefox button on Windows and then approving the new version’s installation after it has completed downloading.
Source: Computer World – Mozilla re-releases Firefox 9, backs out fix causing crash