Flash Player 9 in Safari (Mac)

I've noticed a bug which only seems to occur in Flash Player 9 on Safari, on a mac. When hovering over a button it flickers:

http://content.giantworks.co.uk/buttontest/

Is this a known bug ?

Thanks

Hmmm, have you tried any other browsers? Because Flash isn't like HTML (where each browser reads it differently), it should be fairly uniform. If the same thing occurs in Firefox or Chrome on your computer, I would say it could be a Flash Player 9 thing to do with rendering buttons.

I can't really verify anything as I'm up to Flash Player 11 or so and on a Windows system. I also can't seem to be able to find much about this after a quick search either, unfortunately.