[ubuntu] no wifi after kernel update

Here's my issue. in order to get sound from my headphone jack i need to update the kernel. wifi works fine out of the box with 12.04.1 but as soon as i update the kernel to anything newer than 3.2 my wifi flakes out. i can see the list of available networks but it wont connect. i am using a 27 inch imac 12,2

oddly enough, i can use a usb dongle with no issues.

any ideas???

thanks