In an office a wireless network is configured with Apple's Airport Extreme (don't know exakt model & age).
The wl network can be seen by:
* All Win7 computers
* My old laptop, Medion with LinuxMint 10 Gnome

The wl network can not be seen by
* One Dell laptop with Windows XP
* My new laptop, HP ProBook6465b w LinuxMintDebianEdition & Mate.

I don't really care about the XP, but my laptop simply must connect to the wireless!
I can connect to other wl-networks, at this office I can see about 20-30 different networks but the actual one is not to be found.
I also tried "connecting to hidden network" and entering all details but to no avail.

I have no idea where to start looking as my wireless works fine everywhere but on this one location, I've read all I could find about AirportExtreme & Linux but have found no errors or problems discussed at all.

Any ideas what's wrong - or at least what I should research?

I'm still new to this so this is a guess or maybe a good place to start. Check the firewall on the router. An also if it can only support "x" amount of traffic the. I may not connect. Just a guess ^_^. I'll keep reading here and learn as I go.

The problem is probably a wrong region setting in your wlan driver, this will prevent you from discovering some of the wireless channels.

This may help. I skim through it and it had ideas. http://www.mintppc.org/forums/viewtopic.php?f=15&t=635u