Exact same problem here. Deployed SEPS to 11 workstations, 10 of them went off without a hitch and updated themselves properly. On the 11th workstation, it failed to update itself at all. I could manually update the virus definitions, but the Proactive Threat Protection is turned off and "Waiting for Updates."
I looked in the system log and got the same error as the OP. I've tried uninstalling the client, rebooting, and reinstalling multiple times, to no avail.
"PTS has generated an error: code 11: description: Whitelist Failure"
Even the Symantec Tech I spent 2 hours on the phone with was confused about the problem and told me he'd get back to me with a higher level technician.
If anyone has any information I'd be in your debt, the job is done except for the one picky client :)