[MacDV] horrible glitch!

[Spud0812 at aol.com]

Hi all,
    In the middle of completing a video for my job, I seem to have 
encountered a horrible problem with Imovie Titling....I had to add a cred roll at end of 
video with 300 (!!) names in the "thank yous", it did the title ok, but since 
then, the titling doesnt work anymore in iMovie, (cant update the credits, or 
do any more titling period in any other projects.) Plus when I try to get 
into my Mac to look at memory allocation in iMovie or any other applications, it 
wont even let me look at the memory...doesn't come up for any other 
applications. What could be wrong? Do I re-install iMovie? Please help!
Thanks!