Mozilla plans to release an update to Firefox 5 to fix a bug affecting users of Apple's Macintosh operating system, OS X 10.7.
Mozilla found a bug in the upcoming release of Mac OS X 10.7 that causes Firefox to crash when using downloadable fonts.
Chris Blizzard, a member of Mozilla's product team, said downloadable fonts are widely used on the web so users would suffer severe crash problems.
"We've changed the font APIs that we're using to newer versions, which appear to fix the problem. Users on 10.6 and before will continue to use the old APIs to reduce risk. Later versions of Firefox will move all 10.6 and later users to the new APIs," wrote Chris Blizzard in a blog post.
Blizzard said the update will also fix Firefox 5 so it can load the Java plug-in on OS X 10.5, which broke after Apple updated Java on OS X 10.5.
The update will be the first update to be released outside Mozilla's six-week release model since the transition between Firefox 4 and 5.
Mozilla will update users running Firefox 3.6 to disable downloadable fonts, although Blizzard recommends users upgrade Firefox 5 to avoid potential scrollbar rendering issues.
The update will be made available before the release of Firefox 6, scheduled for release on 16 August 2011.
Firefox 5 was released a few months after Firefox 4, which took a year to release.
IT administrators spoke out about the testing and deployment implications of Mozilla's rapid release process for Firefox, on the blog of Firefox consultant, Mike Kaply, complaining at the announcement of Firefox 4 end of life (EOL).