Allen - yes, I have had the "Always wait for the network at computer startup and logon" enabled for years.

Then, just yesterday, I found out there was another policy called "Startup policy processing wait time" under Computer Configuration\Administrative Templates\System\Group Policy node. I set it to 50 seconds for testing.

Even with these 2 settings enabled in GPO, the Windows 8 tablet still does not run the script. However, after tablet is logged into domain with user and I goto desktop, I can immediately browse to SYSVOL and run the logon.cmd and the script runs perfectly.

Also, I can confirm UAC enable/disable had no effect.