I should have read more closely. I see you have AVG, so no McAfee. That's good. And, your tablets aren't crap.
From reading, do you have both wireless and wired? Is this only happening with the wireless? If so, then that is likely the issue unless Amber's solution fixes it. One of the thing that a lot of users advise on here is to not use wireless connections. Or is your wireless router close enough to your tablets or server?
