Rotate extension

I am running X on a Toshiba M200 tablet which has the funky ability to 
change from tablet to normal laptop format.
In doing this I need to rotate the screen 90 degrees.
Currently I have to restart the Xserver to do this but it would be 
better if it was possible to rotate on the fly.
I know that the XFree86 server doesn't support rotate yet, but the 
freedesktop server seems to. I tried it out but every time I rotate the 
screen it goes black then freezes (no local keyboard input accepted, 
remote access still available)

Is this meant to work, or is it not implemented fully yet?

Thanks
	Chris Debenham