The BIOS update should have took if it was from Windows Update since it should automatically suspend bitlocker. You can check if it was installed using the command prompt command systeminfo.
This may help explain why it is restarting
http://www.vindamedia.com/windows/help/bitlocker-log-in-turns-off-after-60-seconds
It was kind of long, I figured it would be better as a web page. The page was just created and is currently a rough draft so if you see any errors let me know. I didn't want you to have to wait for a final review of the new page.