If you attempted the temporary fix to get your wireless working correctly on your MacBook after the recent Mac OS 10.5.8 update, check out this MacFixIt post before you try to install the patch issued by Apple earlier today.
I reinstalled the 10.5.8 Combo Update, then applied the Airport patch, and all is now working well.
10.5.8 Airport Airport Bug Fixed
Troy Kitch
@troykitch