wrote:

Ever since I installed AR6, when I launch FF, most of the time it
automatically goes to Mozilla's "Check Your Plugins" page. This
never happened before.

Any ideas on what may be the cause of this "Check Your Plugins"
nuisance?

Couple ideas.

In Firefox, enter about:config in the address bar and hit enter.

Search for this:

plugins.update.url

If you have such an entry, take note of it's value. It might be this:

https://www.mozilla.org/en-US/plugincheck/

If it's not that, then whatever it is, post it here.

I don't have (plugins.update.url) in my version of firefox (version 2)
but apparently it exists.

Now you can either do two things:

a) change the url to something else, like "google.com" - or just
make it blank.

b) leave it alone, and create an entry in your HOSTS file to
effectively null out the url. For example, if the value is
what I mentioned above, then create this line in your hosts file:

127.0.0.1 www.mozilla.org

That will prevent your computer from being able to visit www.mozilla.org
from any browser or application, but it should stop the plugin-check
behavior you're seeing. But deleting the entry on the about:config page
is probably the better option.

The behavior you're seeing is not being caused by Adobe Reader - this is
a Firefox issue.