LinuxQuestions.org - Weird behavior of knetworkmanager under Lenny

I used to manualy configure my network interfaces like this>

Code:

# The loopback network interface

auto lo eth2

iface lo inet loopback



# The primary network interface

allow-hotplug eth0

iface eth0 inet dhcp



# wifi 

iface eth2 inet dhcp

wireless-essid mySSID

wireless-mode managed

this is for my home wifi LAN with wifi router and it works like charm. However recently I need to move my laptop a little and I was forced to work under different wifi sites, so some network manager would be handy. I don't need any wifi encryption, and after short research (and after few small utility install and uninstall) I discovered that network-manager is THE way to go. apt-get install knetworkmanger and I changed my interfaces file to something like:

Code:

# The loopback network interface

auto lo

iface lo inet loopback



# The primary network interface

allow-hotplug eth0

iface eth0 inet dhcp



# wifina 

iface eth2 inet dhcp

#wireless-essid mySSID

#wireless-mode managed

So it will not conflict with network manger. I also added myself to 'netdev' group and restarted whole laptop (yes, yes, it is enough to restart some services, but I'm lazy and this is easier..)
However since I let knetworkmanager control my network connections, it acts in weird ways. For example sometimes it completly refuses to connect to my primary network with 'mySSID'. It says 'Unable to connect to mySSID' and it automaticly tries other sites (of other people in the building :> ), and successfuly connects to their sites. This behavior is completely random. I don't know where to start, I didn't find any good guide for network-manager under Debian, all in all, isn't wifi connection one of most obvious functionality that OS should meet? from my point of view it seems to be very poorly implemented.