Systems

Windows XP	Anethron, Centurion, Frostmane, Geico, Max Payne, McBain, Onyxia, Piglet, Praetor, Warlock
Windows Vista	Dragonmaw, Lothar, Norwegia, Silvermoon, Wario
Windows 7 32-bit	Kal-el, MiniHP, Palpatine, Shadowsong
Windows 7 64-bit	Isiset, Satesh, Terminus, Zito
Windows 8 32-bit	Higgins, Skywall
Windows 8 64-bit	Assad, Marwyn, Medivh, Siamat, Vader

Set up the test environment

Download the latest build from archive.mozilla.org
Run installer and select customize
Put the install in a custom directory (C:\Firefox for purposes of this example)
Do NOT allow it to launch Firefox at the end of the install

Run cmd.exe
Change directory to the folder where you installed Firefox: cd C:\Firefox
Run firefox.exe: firefox.exe -P -no-remote - This will bring up our profile selector window.
Use the "Create Profile" button to create a profile new profile
Once the profile is created, select it, and then click "Start Firefox"

Make sure you have installed all the latest Windows updates, including the latest graphics driver.
Start Firefox with a new profile.
Open Youtube.com and start playing the playlist. Change the quality to 1080p60 and let the videos play.
Open a new tab and load Google Maps, select the Earth view and explore the map. After a few minutes, switch back to the Youtube tab and verify the playlist is still playing.
Open a new tab and load Flickr.com. Explore some of the photos making sure you scroll past the bottom of the page a few times. While there, be sure to check the Explore > World Map functionality.
Open a new tab and load CNN.com. Scroll around the page, loading some news articles and playing some videos. After a few minutes, switch back to the Youtube tab and verify the playlist is still playing.
Open a new tab and load Battle.net, select one of the games and explore the content. Scroll around the page and play any videos that appear. After a few minutes, switch back to the Youtube tab and verify the playlist is still playing.
Open a new tab, wait a minute, then close Firefox.
Start Firefox and restore the session.
Drag any one of the tabs outside of the window so it appears in its own window
Drag that tab back to the tab bar of the main window so it rejoins the main window
Quit Firefox

Fill out this form once you've completed the test (one response per system please).

Report bugs for the following issues:

You can use this template to file your bug report.

be sure to attach a copy of your about:support and dxdiag log in the bug report
if the bug is a crash, be sure to include links to your crash reports from the about:crashes page

Full Query

ID	Summary	Priority	Status
1201126	1080p 60 FPS video stuttering and occasionally stopping playback	P2	RESOLVED

1 Total; 0 Open (0%); 1 Resolved (100%); 0 Verified (0%);