Kubuntu 14.04 and trinity:problems with wired network

Hi This is the first time I have such an experience. I installed Kubuntu 14.04 and trinity via deb http://mirror.xcer.cz/trinity-sb trusty deps-r14 main-r14 deb-src http://mirror.xcer.cz/trinity-sb trusty deps-r14 main-r14 Everything went smooth wireless net can be configured with tdenetworkmanager, but when I try to set up the wired net, via the networktool I run into a problem. I use all the parameters I used in previous trinity + Kubuntu installations (namely 10.04 and 12.04) static IP number DNS server Gateway. The connection works for a couple of seconds and then crashes the problem see to be the Gateway, when I restart the configuration tool the value has been deleted. Anybody has an idea what do? That is a very serious problem, right now use the Wifi connection, but this has severe restriction in the network I am using. Thanks Uwe Brauer