Hello Everyone,
I know this is my first post, but before I get to my question, I wanted to say this forum has been extremely helpful to me, and I an hopeful someone might be able to help me out.  My problem is with my Raspberry Pi WiFi because after a few hours, it seems that either the WiFi device goes into a power save mode, or the Pi device enters into some sort of standby/sleep mode.  I've read many different articles in this forum and have even scoured the tubes to find a answer to my problem, and everything that I have tried implementing does not work...

I am using an Edimax EW-7811Un USB dongle.  Initially I had it plugged into one of the on-board UBS port on the Pi device and then I moved it to my 13-port, powered USB hub.  In either case, after a few hours of operation, the Pi or the WiFi dongle seems to stop operating.  The only way for me to enable WiFi connectivity is to unplug the Pi and then plug it back in so the USB dongle turns back on...

The following is what I have tried to rectify my problem:
1.  I added the following line to the /etc/modprobe.d/8192cu.conf...  options 8192cu rtw_power_mgnt=0 rtw_enusbss=0
2.  In /etc/network/interfaces I have:
auto lo
iface lo inet loopback
iface eth0 inet dhcp
allow-hotplug wlan0
auto wlan0
iface wlan0 inet dhcp
wpa-ssid XXTTCC
wpa-psk XXZZXXZZ
wireless-power off

3.  Create a cron job to ping the router gateway every minute

4.  Even used a second WiFi adapter and still have the same issues

Any assistance or guidance is greatly appreciated.  I really am hopeful that I will not have to keep checking every four hours to see if my gridseeds are connected.

-dealerof21