youtube, won't let me add video to my playlists

Not sure this is a "software" issue, at least I don't think it's mine. It's been a while since I did much with my youtube account. Mostly because I also have a Hulu plus account. But I have a few unpublished youtube playlists, And I wanted to update them with a new videos that I hadn't watched...

I searched for, and found a video that I hadn't watched yet. I checked that it really was available by starting to play the video. As soon as I was sure it wasn't one that I'd already watched I paused and copied the url from the location bar to the clipboard. Opened another tab and logged in to my youtube account. Then selected one of my playlists for editing. It let me delete an item I was tired of seeing. It also let me change the order of the videos in the list so I must have been properly logged in.

The problem starts when I try to add the video by clicking on the add video button. I then paste the url into the search box, and hit enter:

When I did that with a freshly updated Firefox under Windows 7, it failed to find the video. (the only firefox extenion I use is noscript. But I opened the noscript panel and there were no sites attempting to run javascript other than those I'd already approved...)

I rebooted into Mageia Linux, and repeated the process This time I had to tell noscript to approve some google site about user content. But when I hit enter on the add video search box, it found and correctly identified the video. BUT it said it was unavailable, and admonished that I needed adobe flash to play it... But when I clicked on the thumbnail sized video it would play the video. It just wouldn't add it to my play list.

I then retreated to my desk. (had some bills to pay) When I was done with the bills I tried again with Firefox, this time under Bodhi Linux with the same results I'd had under Mageia on the other PC. At this point I opened "Chromium {Version 33.0.1750.152 Ubuntu 12.04 (256984)}" {still under Bodhi linux} and repeated the process again. I've added no extensions to Chromium. But the results were the same as with Firefox on either Bodhi, or Mageia Linux. This time I took a screenshot:
http://i59.tinypic.com/5vaviv.png
As you can see, the video in question will play. Even from inside the dialog that won't add it to my playlist...

Since with either computer, and with any of the above listed OS/Browser combinations I can search youtube for, find, and play the video in question, regardless of whether or not I've bothered to log in to my you tube account, I don't think its really an issue with my software. But perhaps there is some new setting someplace or something???

Does anyone have a clue what I'm doing wrong?