You can first try changing the power setting for USB in control panel. This tip works for some motherboards, but i have no idea if it'll help your tablet.
Go to System in your control panel, go to the Hardware tab, hit Device Manager. Go all the way down to your "USB Root Hub", double click on them to open up the properties for each of them, and then find the Power Management tab. deselect the "Allow the computer to turn off this device to save power." Do this for every "USB Root Hub" you have on there.
If that doesn't work (it doesn't for this new motherboard I'm using), what I did is get a powered hub (looks like this but got from ebay: http://www.pcloft.com/sybecousb20h.html). I built a shutdown controller for it so that when the key is taken out, the hub immediately cuts power (essentially unplugging whatever's on the hub) but the carpc is still up for 30 more seconds. It hibernates as if the stuff aren't plugged in. When the key is turned on in the morning, the hub powers up before the carpc does, and it thinks the devices in the usb hub are new connections once it starts resuming from hibernation.