Well, this whole 1.3 BN update has me completely frustrated. I've followed the directions in the first post exactly and cannot get this to work at all. 4.6.16a completely breaks my market forcing me to revert back to 4.5.18.
Also, I now have issues installing apps I had before because of the limited Market visibility issues. This has also cause some of my purchased apps from the Amazon App store to no longer show up as compatible with my Nook....
Wish I could just go away from the stock OS but can't because my kids love the Kids nook books....
I'm in the same boat. I'm assuming that there's no permanent, reliable fix yet to get market access using 1.3 and 4.6.16 as everything I've tried (including side-loading 1.3 then running 4.6.18 and/or 4.6.16) hasn't worked.