Hi eingram,
Thank you for choosing Windows 8 and for providing us an opportunity to assist you.
I understand that the tablet will not function after waking from sleep mode. I will try to help you with this.
1) Have you made any changes prior to the issue?
2) Do you receive any error message/code?
Method 1: I would have you uninstall the drivers and reinstall them.
a. Open the Device Manager by Pressing Windows key + R and typing Devmgmt.msc
b. Display or touch drivers.
c. Please right click and try to uninstall the driver.
d. Restart the computer and update.
Run the Hardware troubleshooter and check.
Method 2: Follow the steps to run the troubleshooter:
a. Press Windows key + C on your keyboard to show the Charms bar.
b. Type Troubleshooting and click Troubleshooting under Settings.
c. Now type Hardware Troubleshooter in the search option.
d. Click on Hardware troubleshooter to run the troubleshooter.
Please post back if you are still experiencing the issue. I will be glad to provide you with the additional options available that you can utilize to get the issue resolved.