Got around to upgrading my 13 MacBook Pro today to 10.7.3 (already had Lion) .Upgrade hung, Left sit for hour and a half and I finally restarted it. Now all I get is a circle with a line thru.I have a BootCamp partition with XP and a Recovery partition I can boot from both of those. I booted from the recovery partition and re downloaded Lion and installed but when it restarts it goes right to the circle with a line thru. I can boot from an external Snow Leopard disk and see everything. Running Disk utility from Recovery HD partition says disk appears ok. I've run repair permissions many times and it always has a lot that are wrong, over and over. It shows the 10.7.3 partition in startup disk choice just can't get to log in screen. Something is corrupted in the start up.