It has been suggested by some that the solution would be to connect using an
ethernet cable and then to update your system then. The theory goes that your
wireless setup will be detected automatically and the proper drivers downloaded.
I may try this after I upgrade.

If you mean you installed 9.10 then did the update to 10.10, as the
post suggests, you would get a better install if you got the 10.10
installer and did this direct - or go for the 10.04LTS version if you
feel 3 years without having to update every 6 months is a better
option for you.

some wireless cards are picked up on
the initial install but some need to be connected by cable first to
get updates before the wireless card drivers are installed.