Actually, if you don't turn OFF AC, simply by disabling it, or taking it out of startups, or unchecking "load at windows startup", the two will battle for your connection. This is root of many problems which people have with the one, or both, they leave both of them on, and the two battle.

So, EITHER, UNCHECK the box listed above to use AC, and keep it running, OR shut down AC, and CHECK the box in the windows wireless advanced settings that says "allow windows to manage my connections"

The new SP2 wireless settings are nice and MUCH better than the old settings, I simply haven't made the move to SP2 on my laptop since there were issues early on, and nothing was gained and AC works great for me.