wlan not found

[anuyahong]

Hello,
I have a strange problem with my EeePC. When I am at my sisters place, it can not find the WLAN there. The WLAN itself is working, I can connect to it with other PCs/mobile phones.
The netbook and it's WLAN is also working - I can connect to WLANs all over the world.
Only when I am with my sister, the netbook simply can not find the WLAN there.
I don't think it has something to do with the PC or the 12/04 Kubuntu version since I had the same problem with my former netbook (Kubuntu 9/something) at my parents place.

Unfortunately I am not deep into Linux enough to have the slightliest idea where to start. Even when I add the WLAN data manually, the PC simply declines to find it.

Anyone any idea, what the problem might be or what I could do for any progress?
Thank you so much in advance,
Frank

[Snowhog]

If your EeePC can't 'see' your sisters WLAN, she likely has the SSID set to 'hidden'.

[anuyahong]

If your EeePC can't 'see' your sisters WLAN, she likely has the SSID set to 'hidden'.

Thanks for your fast reply. But that would be too easy. Every other device finds the WLAN, just this netbook doesn't want it :-)
And what confuses me even more is the fact that I had the same problem with another netbook and another WLAN some years ago already. But than it suddenly works after some days. But this time it's really persistent (every time I am here for more than a year)...
Thank you,
Frank

[Robtygart]

Under System Settings>Network Settings>wireless see if you can manually set it up from there.

[anuyahong]

I have tried that already but get an reply like "authentification wrong". But the pw is right, as just proved yesterday by my new mobile phone...
Thanks.
Frank

[GilGib]

Try different security settings. Or see if they wll allow you to access there router to see the settings,