| It sounds like you've upgraded from Tiger to Leopard (i.e. didn't reformat or archive and install, just did a plain upgrade), and then started to update Quicktime and other OS X components.
From what can be seen, it looks like your installation is hosed. I do not think there is anything that can be done apart from backing up your data and doing a clean install. Of course, you should wait for other opinions first but I do not think there is anything else you can do. |