Sin puntuar aún

Didn't get a single download to work. Crashes FF in no time.

Esta valoración es de una versión anterior del complemento (0.8.8). 

There have been no other crash reports, so I tend to believe your problem is not FlashGot related.
Anyway, it would be more helpful if you reported on the Mozillazine forum thread ( http://flashgot.net/forum ) or directly to me by email, specifying what download manager you're using and on which pages your crashes happened. Whatever you write here (on AMO) is not notified to authors, hence it can be read only casually.
Thanks.