I have a problem with my notebook acer aspire v3-551. It works with Ubuntu 13.04. The problem is that wifi connection always falling down. It goes randomly. enter link description here - here you can see some logs when the connection is breaking.
Also I changed by myself the channel of wifi on the 3d channel. The network card is Qualcomm Atheros AR8151 v2.0 Gigabit Ethernet