[ovirt-users] ovirt-guest: Network device hanging shortly after startup (after Upgrade to 4.3.5)

We have a some old guests (SLES 10.4) which has been worked corectly till 4.2.7 (Manager + Host) After Upgrade to 4.3.5, we have got a network issue, that the gues network device, not depending on used device type, stopts to work after some seconds.... after about 15-20 pings device is hanging. Sometimes, in the first time after the device hungs up, the message "no buffer space available" comes from ping. Does someone knows a solution for it? greetings Julius