I've seen these before, although I hasten to add not on PSG.
Its a gfx driver issue, or to be more precise a conflict between your gfx driver and Adobe Flash, (You might have guessed), And browser accelerated graphics.
If you use Firefox try this:
Update Firefox.....latest ver is 32.0
Update Adobe Flash Player (For both FF AND IE!)...latest ver is 22.214.171.124
(My FF didn't recognise this as a 'plugin' update but it is available)
If that doesn't solve it also try:
Tools > Options > Advanced > General and UNCHECK 'Use hardware acceleration when available'.
If you don't use FF then do whatever the equivalent is for your browser.
Can't guarantee this will work for you but it has worked for me in the past.
One things for sure...its not a PSG issue.