Firefox preventing noscript install

[eradic8]

I just went to download the latest stable version of noscript and was prompted by Firefox with the following message:
Firefox prevented this site (noscript.net) from asking you to install software on your computer.

My only reason for mentioning this is that this did not happen the last time I downloaded noscript from the site so I could not understand why it is bringing up this message. In the past I have waited for Firefox to automatically check for updates but it is slow at checking for updates so I decided to check daily for noscript updates myself. I could of course have allowed install, but I thought I would just check with this forum first to make sure there are not any problems and that this is normal.

[Giorgio Maone]

Yes, it is normal.
The only web site which can install extensions in your browser without that warning bar is AMO.