Wi-fi keeps disconnecting and asks for authentication in mint 16

[Svilen]

I am having a problem that a lot of users seem to have a variation of - my wifi connection keeps disconnecting every couple of minutes and asking for me to authenticate it (by opening a windows and if I am away it will open 10-20 of the same authentication window). I have it set to auto-connect so I have no clue why it does this and after trying some solutions from the forum (such as having it as the only remembered connection) I still haven't managed to fix anything.

However, even if I click 'connect' on the authenticate window usually the connection becomes unstable so I have to turn off the wireless and turn it back on every time. I have to do this every 2-10 minutes and it is very annoying.

We recently switched the router at home but other devices don't seem to have it as bad. The main difference is that the router works both in 2.4 ghz and 5 ghz while (I believe) the older one broadcasted only in 2.4.

'$ iwconfig
eth0 no wireless extensions.

lo no wireless extensions.

wlan0 IEEE 802.11bgn ESSID:"BTHub5-HT2G"
          Mode:Managed Frequency:2.412 GHz Access Point: 00:62:2C:3E:DD:38
          Bit Rate=72.2 Mb/s Tx-Power=16 dBm
          Retry long limit:7 RTS thr:off Fragment thr:off
          Power Management:off
          Link Quality=56/70 Signal level=-54 dBm
          Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
          Tx excessive retries:0 Invalid misc:534 Missed beacon:0'

'$ lspci -nn | grep Net
03:00.0 Network controller [0280]: Qualcomm Atheros AR9485 Wireless Network Adapter [168c:0032] (rev 01)'

'$ lsmod
Module Size Used by
ath9k 151173 0
ath9k_common 13859 1 ath9k
ath9k_hw 444645 2 ath9k_common,ath9k
ath 23827 3 ath9k_common,ath9k,ath9k_hw
mac80211 596969 1 ath9k
cfg80211 479757 3 ath,ath9k,mac80211
...
....'