I have an original Mac Pro. Yesterday I installed the security update. After the installation, the computer did not shut down properly. Even holding down the power button did not help. I had to pull the power plug. Now the Mac takes about 4 minutes and 30 seconds to boot. I have OS X installed on three individual drives (two SSDs that normally would boot in 20 seconds), both 10.7 and 10.6, and they all, strangely, takes the same time to boot now. After the chime sound, most of the time it now takes about 1m 20s for the login menu to appear. Then it takes another 3 minutes before I can actually click on anything. Other times the grey screen turns blue after 1m 20s and then it stays blue for another 3 minutes before the login menu appears. When the computer finally has booted, everything seems to work normally. Any ideas what might have happened and how to troubleshoot this?