Flash player freeze a lot when playing Youtube videos fullscreen from Linux, but plays ok from Windows (CPU: AMD APU)

Flash player freeze a lot when playing Youtube videos fullscreen from Linux, but plays videos ok from Windows (CPU: AMD APU).

When playing video in default size it's OK (windows and Linux), but when setting video in full screen, on Linux there's troubles: video is hashed (freeze every 3 seconds).

CPU : AMD APU Athlon 5350.

OS : Linux Mint 17 (64 bits).

Browser: Firefox v31 (on Linux and Windows 7).

Linux AMD video driver : Catalyst v14.4 (amd-catalyst-14-4-rev2-linux-x86-x86-64-may6.zip)

Linux Flash polayer version: 11,2,202,400 (deteced from https://www.adobe.com/software/flash/about/ )