This may explain why...
QUOTE
Here is the fact, NO mac currently using an Atheros based AirPort card will work in 64bit mode in 10.6.0 until/unless apple fixes the driver and cannot be disputed, so, MacBook, MacBook Pro, iMac, Mac-Mini and MacPro owners who have an Atheros based Airport card and rely on wireless connectivity have no wireless in 64bit mode although the Mac-Mini (1,1) is working so it must be booting in 32bit.
http://lists.apple.com/archives/macos-x-se...p/msg00237.html