This upcoming Thursday the QA team of Thunderbird is organizing a Linux Bug day - we will try to target and add information to bugs that affect the linux platform. With the help of packages maintainers from Fedora, OpenSuse and Ubuntu, people using these distribution will be able to install a nightly build of Thunderbird using the systems package management tools. The bugs that we would like people to comment on are in the UNCO state - meaning - they need more information (crash stats, steps to reproduce, etc ...) for to be able to be fixed by the developers.
More information on the event and how to participate is available at : https://wiki.mozilla.org/Thunderbird:QA_TestDay:2009-05-14