I have migrated over to a new PC with Vista Business installed.

Everything was working fine - then I installed ALL available updates. I now
have a problem when developing Flash games, they pause when any code is being
process - http://www.donpixel.com/play/en/060421094956/ - this Optus game
pauses everytime I either click the ball or the ball bounces (everytime the
game processes a function / hit test I assume)

Is anyone aware of the update which causes this 'juddering' or 'pausing'... as
this has now happened on two brand new and individual machines - what is the
problem!

I am also experiencing this problem using Flash Player 9.0.45 in both IE7 and
FF2.0.0.3 in Vista Home Premium.

The problem occurs when playing any flash content that accepts input from the
keyboard (mostly games). For example, Miniclip's Bubble Trouble
(http://www.miniclip.com/games/bubble-trouble/en/). Using the arrow keys
doesn't seem to affect flash player, however, each time the space bar is
pressed a 1/2 to 1 second pause / stutter occurs.

I have uninstalled and reinstalled flash player in both browsers multiple
times and the problem reoccurs.

Yes, and FF2.0.0.3.

I have used the standalone players for Flash 7 and 8 under Vista (I assume this
means I'm not using IE7) with my games and I still see the stuttering. Also, I
just upgraded to the latest Flash CS3 Pro and the stuttering still happens. If
I go to the web site listed in the original post, it stutters for me using IE7.
Everything works flawlessly under XP using the exact same players/apps so it
really seems to be something that is Vista specific.