I have a laptop which is running xubuntu 8.04. I am using a wireless USB adapter (you know, looks like a USB stick, you plug them in, and you have a working wireless). When I plugged it in, it immediately showed up in the network manager, and I only had to configure it. And it worked. I could browse, use IRC, you name the lot.

But suddenly, the wireless connection was gone. So I opened the Network manager, only to discover that not only the wireless connection had gone, but that the wireless USB adapter didn't show up anymore either.

Anyway, it is a fresh install of xubuntu. I installed it using USB, because the CD-ROM drive isn't working. The installation went fine. No problems at all. The wireless AP is hidden, 802.11g, using channel 4, and encrypted using WPA2 Personal. The wireless USB adapter is from the brand König (don't bother Googling it, you will find nothing useful).

If you need additional information to help solve the problem just ask me. I will be happy to provide it.