Last night I installed eeeUbuntu8.04 on my Acer Aspire One.
It runs perfect with one exception: my wifi settings are not stored properly.
Every time I start or restart the computer I must again edit the wifi configuration.
Is there a method to store these settings in a way that I do not have to configure them every time?

Are you using "Network Manager"?

It is buggy.

Uninstall it, add this line to /etc/apt/sources.list Then
sudo apt-get update
sudo apt-get install wicd

wicd is a much better "Network Manager"
If that fails, then just edit your /etc/network/interfaces file and list your wireless connection there. There are plenty of HOWTOs on the net for this procedure.

Thank you for your advice but unfortunately wicd does not work as desired, it does not detect my wireless network at all.
Then I am helpless because there is nothing to configure without a proper detection.
So I reversed the measure and reinstalled network manager, because it actually is able to detect my wireless network.
I will Google my way around to find the necessary knowledge of wicd.

NM doesn't detect your wireless network, the kernel does that. NM is used to configure your wireless connection. And sometimes it doesn't do that very well.

So, let's just go back to basics:
Please post the output of
sudo iwlist scan
sudo ifconfig
cat /etc/network/interfaces

Are you using wireless encryption?
If so, what sort (WPA WEP etc.)?

In that case I assume a communication problem from kernel > wicd, because NM actually reports a detection and wicd does not.
The detected wireless network is really there so why does wicd report no detections at all?

I'm not going back to basics for the problem has already been solved.
Minutes ago my netbook finished a version upgrade from Ubuntu8.04 to 8.10.
Ever since I can shutdown and/or reboot as much as I like without loosing my wireless connection.
Fyi: I use wpa2 for encryption.

When I installed LinuxMINT 5 yesterday, I encountered what I believe to be the same problem you saw with wicd. What I discovered was that, as long as I had my wired NIC plugged in, wicd didn't look for a wireless connection, and therefore didn't show one as available. Disconnecting my NIC cable and then issuing an ifdown/ifup for my ath0 interface allowed wicd to then look for the wireless access points. I configured mine and logged in through it just fine. It has kept me connected through both reboots and full shutdowns/cold boots since.

A good point. Thanks for the follow-up.
But he seems to have got it working even if he'll never know why.