[Bill Lee]

Try:
Going to the Tools>Render Manager

[Bill Lee]

Try:
Running Font Book,
Select all Fonts (Cmd-A),
File>Validate Fonts
Watch out for bad (damaged) fonts that may be creating problems for the font selection.

Now, I must admit I have no clue what you mean by:
“I cannot change the font in the text tab all of a sudden.”
Are you referring to changing the font in one of the text video generators? If so, which one? Some of the ones supplied are really only appropriate for maintaining backward compatibility since the availability of Text 3D and Livetype.

Have you done the usual troubleshooting sequences?
– save, quit and reopen FCP – does the problem still occur?
– reboot computer and reopen FCP and your project – does the problem still occur?
– close your existing project and create a new test project – does the problem still occur?
– create a new user, log in as that user and create a new test project – does the problem still occur?
– open your old project whilst logged in as that new user – does the problem still occur?
– install a new copy of Mac OS X and FCP on a spare drive and open your project – does the problem still occur?

Cheers,
Bill Lee