Darwin Login Screen?

I ran Security Update 2007-004 and Quicktime 7.1.6 from Software update. QT failed and I was prompted to restart. When I did the computer comes up with the login on the Darwin BSD screen. I can't get past it. I can boot in target mode so I am able to mount the PowerBook HD on my iBook. There are a few posts on this topic, (Darwin login screen) but I have not been able to get a solution from them. I have also tried to install QT from the download file, but get the message that this will only work on a booted drive. Can anyone offer a suggestion?