As near as I can tell, you do have to register the once before you can use it...
This fella says the same
http://john.nachtimwald.com/2011/06/11/nook-str-review/
HOWEVER all this usually requires is a WiFi signal & an email account ...somewhere...anywhere...and the bother of setting it all up at B&N online. After that you can shut off the wifi and sideload all your old DRM free books you had already or the lovely public domain books from manybooks.net or Gutenberg Project et al
Does sound like yours is being a pill about going online the first time. I had no trouble with getting mine to register & I already had an account. The only thing I can think of is to check that its looking for the same kind of encryption you are actually using on your router?
http://en.wikipedia.org/wiki/Wireless_security
http://www.smallbusinesscomputing.co...ity-at-All.htm