I have the "You need Administrative privileges to use SPTI" issue on a Win7 box (with Daemon Tools and SPTD installed as well). I only have the issue when logged on remotely (using and administrator user) via RDP, not when I logon locally. I tried both with a local user logged on and without, same issue.
I tried the Security Policy fix from the FAQ (http://forum.imgburn.com/index.php?showtopic=59&st=0&p=969entry969) but it didnt fix it.
Then I tried uninstalling and reinstalling via RDP/admin user, choose the "Allow SPTI for all users" option during install and allowed the installer to start the program, and it worked..... until I closed it and restarted the program, then it stopped working again....
So this must be something that ImgBurn is able to fix via software, since it worked for the first start of the program?