AFAICT, the TEW-423PI does not work out of the box on 10.04. Googling seems to suggest the need for proprietary drivers or ndiswrapper.

Some more information can be found at here, for slackware, rtl-8185 chipset in general, here for tew-423pi, not ubuntu-specific, Account of woes on Ubuntu

As someone who bought a TEW-423PI on the strength of this page's recommendations, I'd really like to see the claim that it works out of the box either removed or a pointer added to information that supports that claim.