FlashGot has received a brand new update today, so users who have previously installed it are now recommended to get the latest release as soon as possible.
Basically, FlashGot 1.5.5.9 RC 1 is supposed to improve compatibility with Firefox Nightly, so the app restores the functionality of the built-in download manager in this particular version of the browser.
According to the developing team, all issues have been caused by the new JS Downloads API, but everything should work just fine in the new build.
At the same time, version 1.5.5.9 RC 1 packs cleaner DTA auto-detection, as well as updated languages, so a slightly improved experience should be provided after deploying the update.
FlashGot continues to work with all Firefox versions, but also with Thunderbird and SeaMonkey.