"Boot Camp x64 is unsupported on this computer model"

i am attempting to install drivers for 64-bit version of windows 7 on my Macbook Pro i got in September 2010, and i keep getting the message listed above. According to the following link: http://support.apple.com/kb/HT1846 , my computer should be able to run 64 bit windows through bootcamp

the problem may be that the mac osx installion disc i am using is out of date relative to my laptop. how do i get a more up to date Mac OS installion disc?