Greetings,

I recently bought a smartphone and wanted to connect to the mobile internet using my fone. I can attach the fone via USB and select “Modem mode” and it pops up in network manager plasmoid (KDE 4.5.2) as “usb0”.
Whenever I click on the mobile connection, the wired eth0 disconnects and instantly reconnects, leaving me no chance of connecting via the mobile internet.
The only way to make him use the mobile internet connection is unplugging eth0 wire.
It shouldn‘t force me to use wired connection?
Also checking or unchecking “Use wireless connections” did help nothing.

(KDE Network manager is a mess since ever unfortunately…)

That is not expected behaviour. Can you check with nm-applet to see if it experiences the same problems?