Got a iPAQ 4150 P-PC 2003

I've got myself stuck whilst playing around with the Wifi
Authentification settings.

Basically I can't get out of the 'Configure Network Authentification'
dialog box. No matter what options I highlight, clicking OK results in
a "The network key you entered is not correct. Please try again" error
message.

As I don't actually have a valid 'network key' to type in, I can't get
out of this dialog box.

The "The key is provide for me automatically" is grayed out and any
combination of "Data encryption (WEP enabled)" or "Network
Authentification (Shared Mode" doesn't help either.

Heeelppp!!