Another thing that might help if you have not done this yet....
Try disabling the power saving mode of your network adapter from Device Manager.
Type Device Manager from Start Orb
, see on the top Device Manager, locate Network Adapters double click on it right click on the problematic Network Adapter and choose Properties, find Power Management Tab
uncheck the boxes if they are checked, click Ok. Now, see if the issue persist and give us an update.