FCP 5 crashes on launch after software update

Hi all, I would be grateful for any pointers as I'm tearing my hair out on this one.

I've been running FCP 5.0.4 with no problems for nearly a year.

Last night I ran a substantial set of software updates, including the one for readiness to upgrade to Lion.

Today, I cannot open FCP. After clicking to open the application, I constantly get the dialog: 'Final Cut Pro quit unexpectedly'.

First, knowing it's usually the solution, I trashed my preferences.

Next I looked into uninstalling FCP with an eye to reinstalling it - didn't realise this would be so much of a minefield...but eventually I ran FCS Remover 3.0.1, telling it to remove everything.

Then I reinstalled FCP. And again, the same 'Final Cut Pro quit unexpectedly' dialog.

I've searched for a solution - no preferences to trash any more as I can't launch the **** thing.

Some have suggested repairing permissions through the Disk Utility - no change.

I've seen instructions to do with prebinding in Terminal from Apple here: http://support.apple.com/kb/TA27807?viewlocale=en_US, using the command line: sudo update_prebinding -root / -force

Terminal asks for my password, then says 'command not found', same again on repeated attempts.

With my limited Terminal knowledge I don't want to go any further. I'm seeing other people reporting similar problems after software updates, but no solutions - I'm not sure if this is a problem unique to me or something more widespread.

Can anybody help? Is anybody having similar issues? I'm worried I'll never be able to run FCP again. Disaster.