"You have version 10,1,53,7 installed" is what Flash Player tells me.
I'm using FF 3.6.3. for the browser.
Edit: Just installed the latest downloadable public release. Side screens still turn white when I use Full Screen for the video.
"You have version 10,0,45,2 installed"
NOTE: Isn't this a step backwards, though? ???
Further NOTE: FWIW, I did download and install the latest Pre-release. Still white screens on the side.
~Windows 10 x64 Professional
~Gigabyte Z77X-UD5H~Intel I7-3770K~8x2 GB DDR3 Crucial Ballistic 1600 RAM (Dual Channel)~RealTek Onboard~XFX R9 390 8GB GDDR5
~3 Acer 27 inch LCDs~SCEPTRE 505 4K UHD TV
and one Sanyo 32 inch HDTV connected via Intel onboard GPU~SATA BluRay RW~1000 W PSU~And a Whole Lot More!~AND....1 TB XBOX ONE~1 PS4 with Uncharted Bundle~
If you have an issue with what you said, please resolve it in private ;)