I did not post this although it has been out for a few days. The previous version 3.5.4 seems to have lots of issues crashing my plugins. I am not sure how much is changed, but according to the change log, this is what is listed:
Firefox 3.5.5 fixes the following issues:
* Fixed several stability issues.
There do not seems to be any security fixes in this release.
Well, needless to say, the place to download the update will be from: