Thanks for the reply. I've tried that, all the other commands are working perfectly. I've ra:
'tar -zxvf wireless-regdb_2009.11.25-1.tar.gz'

Then I ran:
cd wireless-regdb_2009.11.25-1 without...

When I try run cd wireless-regdb_2009.11.25-1.tar.gz I get the following error:

bash: cd: wireless-regdb_2009.11.25-1.tar.gz: Not a directory.

Any ideas? I've bought this card today.