It also seems not to like the 5Ghz channel (from an Asus RT-N66U) though this was true under Win 7. So I upgraded to an Intel 7260 which is performing flawlessly.
BEFORE Changing the WiFi card
- Download the Middleton BIOS iso.
- Download rufus from pendrivelinux.com
- Follow the instructions at pendrivelinux to format the usb drive as a bootable DOS disk.
- Copy the files from the Middleton BIOS iso to the usb drive. (either mount it or use 7-zip to extract the iso contents).
- Make sure your battery is near fully charged (battery icon is green not yellow on thinkpad indicator).
- Disable the TPM chip in the bios.
- Suspend BitLocker if it's on.
- Boot from the USB drive.
- Run the flash utility (lcreflsh.bat).
- Wait for several minutes.
Changing the WiFi card
- Follow the instructions here for removing the wifi card.
- Insert your replacement wifi card.
TPM can then be re-enabled and bitlocker resumed after rebooting.