I'm using an N dongle with Ubuntu Studio 11.04.

Internet access provides no problem at all, but my home network
(Windows) does.
(This is being investigated.)

The Sitecom WL-344 dongle I originally intended to use wasn't at first
supported, but about a month ago it passed my test.
Apparently, an Ubuntu update has fixed this.
(I'm however using an older Sitecom WL-302.)