Updating Nook from Rooted 2.1 to CM7 or HC?

[IsoGen]

If I already rooted my Nook with 2.1, how can I update it with a CM7 or Honeycomb?

I've burned an image of Clockwork Recovery (8gb) onto my 8gb card, and have also copied zip files for HC. I've placed the SD card into the Nook but after pressing and holding down the power for 10+ seconds, the Nook does not load.

Firmware: 1.1.0
SD card format: FAT32
SD card size: 8gb
Files: Burned image of Clockwork Recovery 8gb, HC-v4-emmc-2nd-edition.zip
Result: Nook does not load

I reformatted the card and tried re-burning the image of CWR to the SDcard and placed the CM7 zip files onto the card.

Result: Nook does not load.

However, without the SD card, the Nook Color loads.

What am I doing wrong?