Issues with the code in version 1.0.5 of FireFox and Thunderbird that were released last week may mean that that release will be short-lived, and that 1.0.6 will be with us very soon. Code changes have seemingly unintentionally stopped some third-party extensions from functioning correctly.

"There is a very real chance that some of the general security improvements in last week's 1.0.5 update may impact a number of extensions that worked with 1.0.4 and earlier, and we want to identify and address as many of these as possible before we release 1.0.6," Mozilla representatives said.