Firefox 38.0.1 / uBlock 0.9.8.1 / no other extensions for the purposes of this example

Hypothetical case:

• Click a link on "example.com" (where scripts are whitelisted or noop)
• A new tab opens to "example-2.com", where scripts are in default deny
• Switch back to "example.com" tab: it's now using the example-2.com's rules, so scripts are blocked

Before clicking link, all is well:

After opening link (t.co is noop as per my own rules):

This is on tweetdeck.twitter.com, where opening a link will cause t.co rules (or if not t.co, any other domain) to take over the original tab, thus tweets and other things will no longer load. I have to refresh the page to fix this.

Another example would be on twitch.tv, where clicking a link in the chat will open a new tab and the video will stop streaming.

No such issue occurs in Chrome.