I had this same problem and I have video taped it for people to confirm that it is the same problem.
it was caused by using the Migration Assistant with Apple Mac and it mucked up the FileVault2 situation and a bunch of file permissions. I have since resolved this problem. Click the link below to view the video I made and view the resolution.
https://www.youtube.com/watch?v=6gDi5hKxyrA&feature=c4-overview&list=UUJJtYCukqfoSKndDcJzgd6w
This has been resolved. The steps to resolve it are as follows:
1) Make a full and complete backup using Time Machine to the External USB drive
2) Reboot the system and hit <Command>-R to go into recovery mode
3) Enter Disk Utility, Format the INTERNAL hard drive with a new File System
4) Let the system reboot, INSTALL A NEW OS from Internet Recovery (it will automatically do this if you just say “reinstall OS"
5) Log in and make sure that your user is NOT in the system, just a simple ADMIN user, delete corporate user name
6) Reboot the system and use <Control-R> again to boot to recovery mode
7) Use the "Recovery from Time Machine backup" option and recover system user and software (this is pretty cool, you can grab all the apps from before too) - be sure to recover ONLY the user you need, not the admin user or any other users.
8) Reboot the system cleanly and notice that it's a SINGLE log in required, no longer 2 and all your data is there. WOHOOO!!!!
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