Elementary OS (Ubuntu Derivative)
Also tested on WIndows 7 64bit
Mobility Radeon 5650
Broken: 2.7 release 64bit, 2.7 RC2
Worked: 2.69 release
Short description of error
While playing animations and doing Toggle Full Screen of the editor (shift+space, ctrl+uparrow), the animation stops playing. Behaviour in 2.69 and earlier was that animation kept playing regardless of Toggle Full Screen of an editor window and it's (at least for me) prefered behaviour. The release notes don't mention any changes so I'm guessing it's a bug.
I tested this with a file from 2.69 and with the default, load factory settings, scene in 2.70 and got the same result.
Exact steps for others to reproduce the error
Press Alt+A to start playing animation (any scene is fine, including default 2.70 scene)
Press shift+space or ctrl+uparrow to toggle the editor window full screen, the animation playback stops.