MOUNTAIN VIEW, CA – Microsoft browser and email client users long ago became accustomed to frequent bug fixes due to the popularity of their products. This month the open-source Firefox browser and Thunderbird e-mail client have had their share of problems, with a second update within a week scheduled for release soon.Last week’s 1.0.5 security update appears to have been flawed, accidentally blocking some third-party extensions from properly functioning. Given that these extensions worked fine in earlier versions, an update can’t come soon enough for many — and Polish users are already frustrated that the flawed version is not available in their language.

Mozilla Foundation representatives say they will not be rushed and are moving cautiously to ensure that the upcoming fix is sound. The foundation has requested that all of its developers temporarily cease work on non-English versions of the current version in order to focus attention and energy on version 1.0.6 for the stand-alone applications and 1.7.10 for the Mozilla Suite. The decision has drawn criticism from those anxious for updates, particularly outside of the U.S., where some developers have urged Mozilla to release all updates simultaneously regardless of language.

Foundation representatives are asking third-party developers to put trial versions of the updated software through heavy testing to ensure that extensions work. According to spokespersons for the foundation, “Extensions that interact with web content and events may be the most susceptible to these changes.” Testing results for mail-handling extensions are of special interest.