CD drivers are the only ones that work? xfire

So I put the driver disk that came with my two 3870's and install pretty much everything. My crossfire works beautifully now, I get 16500 3DMark06 scores.

I upgrade my driver to the 8.4 and crossfire says its enabled but it isnt working anymore, I notice my games are a tad slower and 3DMark06 is getting 11000 scores.

I then try the 8.49 beta drivers and still the same thing, it says crossfire is enabled but it sure isnt, lol. After getting furious with this I uninstall everything and put the driver disk back in and crossfire magically works now

So my question is...Is there a certain way to upgrade drivers if you are running a crossfire setup?

Thanks for the help