Our wifi issues may be unrelated to the OP's but this is what I found.
My partner kept finding her desktop PC would lose the wifi link and then fail to reconnect without rebooting the machine. Doing wifi network diagnosis and repair would not get her back on line. I have a utility on my netbook which monitors wifi and bluetooth signals. It showed the signal from our router being intermittently swamped by BT_fon, there were multiple incidences of BT_fon and all were jumping all over the channels on 2.4GHz wifi. I tried bumping our router to several different channels but the BT_fon always stepped all over it. The affected PC is at the front of our property and the wireless router is at the rear. This arrangement is called for because I use the signal from the wireless router for connection to my computer in my workshop in the rear garden. I also see internet dropping out occasionaly but I have an on screen display of wifi signal strength and quality which never drops, the loss is clearly on the incoming phone connection.
In our case the solution has been to use a bunch of powerline adaptor network links to get the signal from the router to our Freeview hard disk recorder, to her PC and also to a network enabled printer in another room. We still have internet dropping out at a low incidence level but all machines pick up where they left off when the router gets the live internet link restored.
Rans6