Atheros AR9485 wifi disconnects randomly

I have a Lenovo with a AR9485 but I don't have any close neighbors with wifi and your channel and regulatory settings are the only issues I saw. I know chili555 would suggest using 20Mhz instead of 40 if you have that option on the wireless router

Here is one of his posts copied:

First, check the settings in the router. WPA2-AES is preferred; not any WPA and WPA2 mixed mode and certainly not TKIP. Second, if your router is capable of N speeds, I have better luck with a channel width of 20 MHz in the 2.4 GHz band instead of automatic 20/40 MHz. I also have better luck with a fixed channel, either 1, 6 or 11, rather than automatic channel selection. After making these changes, reboot the router.

Next, I recommend that your regulatory domain be set explicitly. Check yours:

sudo iw reg get 

If you get 00, that is a one-size-maybe-fits-all setting. Find yours here Then set it temporarily:

sudo iw reg set IS  

Of course, substitute your country code if not Iceland. Set it permanently:

gksudo gedit /etc/default/crda

Use nano or kate or vim if you don't have the text editor gedit.

Change the last line to read:

REGDOMAIN=IS

Proofread carefully, save and close the text editor.

Next, I'd set IPv6 to Ignore in Network Manager