So safe mode works, and the system is clean. You've reinstalled with the latest version...
Suspect background application conflicting. Run msconfig and disable all other background applications from the startup tab. Reboot and scan. If it works, reenable them one at a time until you've found the culprit. Also turn off the auto liveupdate, you can throw an icon in the shortup to luall.exe, so it runs on bootup. If you append -s to the end of it, it will run silently.
Matt J.