URGENT UPDATE: Using distribution.ini to set extensions.disableScopes does not work in Firefox 8. I've opened a bug for this. The only workaround is to create a JS file in the defaults/preferences directory (you will have to create this directory) where Firefox is installed and set the value there:
Also, note that the correct value to disable this feature is 0 (zero).
I've received my first email about the fact that with Firefox 8, users are now asked if they want to disable your CCK, depending on how you chose to install it (probably in one of those places that Mozilla now considers "forbidden")
If you have NOT deployed Firefox 8, in your organization yet, you need to read this article about disabling the various dialogs that appear.
The problem is that you need to set these preferences in Firefox 7 via something like the CCK so that the dialogs won't appear. If you're already moved to Firefox 8, it's too late.
In the future, it is now recommended that you ship your CCK using the distribution mechanism which I documented last year.
Honestly, there's no really good solution to this for enterprise, but the right place to participate in the discussion is the Enterprise Working Group Mailing List. (Although there isn't much discussion going on there anymore.)