Hey Josh,
A lot more information is needed. Starting with the product key (or product keys) that the customer is using.
My guess is that the customer is disabling network adapters. The solution: don't do that.
The longer-term solution: use TurboActivate 4.0 when it's out very shortly (it works around this interesting user behavior, as well as fixing other possible false negatives).
But we'll only be able to tell you for sure what's happening if you give us more information. Shoot us the product keys at support@wyday.com and we'll take a look at it.