Did the Firefox 'pin tab' function get broken?

Factual Questions
1

I only discovered Firefox’s ability to “pin” a tab within the last year, and it was a wonderful discovery since I don’t keep the browser open all the time, but have two or three continual-use sites that are very convenient to have pinned up there. (SDMB, natch, and Pandora and a local web interface for my network manager.)

The feature worked better than I could have hoped for a long time, down to things like opening the pinned tab if I tried to open a new window for that site, and opening a new tab if I tried to open a bookmark while on a pinned site. One of those cases where the tech really was a little smarter than me, and helped more than it got in the way.

Then, maybe a month back, it stopped being so helpful, and I am perpetually finding a junk window opened in a pinned window, or one of my standards opened in a new tab, and so forth.

Did something change (I am running… let’s see… 33.1.1, and just checking forced it to do that x.x.1 update in the middle) with a recent update? Are there deep configuration settings I can use to push around this behavior?

2

Bump,mostly.

I noticed a couple of curious pages popping up in *Slate *with FF but I hadn’t thought to check pin-tab. Will keep an eye open.

3

If you are in a pinned tab, and then enter a url in the address bar, it will open in that same tab. So now that page is pinned instead of the one you originally pinned. I think you can still use the back button to get back to the original page.