There will be an easier way that this but I cannot think of one at the moment.
Install it, then uninstall in add remove programs which will take you back to IE6.
Go to control panel security center and turn off automatic updates. Go to MS updates site and scan for updates, it will find it again, highlight it and select do not tell me about this update again.
Just out of curiosity what problems did you have with it before and was it a Beta version or the final release?