My first guess would be some form of battery stretching app is disabling your data connection. I have this problem with my WiFi when I am at the limits of the range.

I have also sometimes seen the effect where data is turned off and will not automatically turn back on. What I do is go into the BatteryXL app and left swipe to see the list of radios and turn on data there. This always managed to bring the data connection back to life.

Still, I am beginning to think that the battery stretcher(s) are more trouble than they are worth.

Hope this helps...

Regards,
Eric Ritchie.

 

I've got a similar problem. I use Exchange Activesync and it works well, but twice now it's stopped working for no apparent reason. Samsung's answer is to reset to factory defaults and start again. This worked OK but isn't a long term solution.

I've also got an SII and have experienced no problems with this. Both phones connect to the same Exchange 2010 server, but the Note keeps losing email connectivity. Any ideas?

 

I get this from time to time but for sure it has to be app related. It never happened until after i installed/removed so much crap there was no way to actually know the root cause. It only happens sometimes and when it does turning on airplane mode then turning it off will kick it in gear. I will reset my phone in the near future to see how that plays out. Did try a battery saver app a while back and that may have screwed something up.