[SOLVED] Failur to connect to a known network

[Max2009]

I am using Mandriva 2009.1 KDE 4.2
I was on a wirless network, and suddenly it died. When I went back to try to connect it wouldn't work.
I can connect to another, different network, but not the first one.
When I launched the network center from the terminal and tried to connect to the original network I got the following output.

Error for wireless request "Set Mode" (8B06) :
SET failed on device wlan0 ; Device or resource busy.
got connection status event: interface_down wlan0
got connection status event: link_up wlan0
got connection status event: dhcp_request wlan0

And that was it. After that the gui told me it couldn't connect.
So, uh, what is the problem and how do I fix it?

[ursusca]

Probably anybody changed the settings of the DHCP server???

[Max2009]

Um, maybe.
It's not my network, but I can hack into the admin page. But not until after the weekend.
What am I looking for and what should I do about it?

[ursusca]

You have to MAC Address Filtering.

[Max2009]

The admin accidentally turned on the MAC filter.
I fixed it.