I also think its partly Kongregate that appears to be slowing the game so much, it runs fine on my own webspace.
http://members.optusnet.com.au/da-bomer/gametest9.html
Thanks all who posted comments, I'm very impressed by the quick feedback. Just a few things, WOW, this runs absolutely horrible in a browser. I've doe most my testing in .SWF projector and it runs at a solid 60fps, nearly twice the speed. Clearly its a very different picture here.
Over this weekend I'll try and make some tweaks, I presume its the aliasing on the vector splotches around the blocks that are causing the issue.
Very sorry for the god aweful performance. I also hope to implement the global high score table that Kongregate offers, and a few gameplay tweaks I have in mind. Thanks again to everyone who made comments, very impressed by the potentials of this community and I appreciate everyone who played and commented on my first test project!