Logic Studio 9 won't install again from original DVD.. help!

Hey guys,

I've been having trouble with Logic studio 9 for a while.

For some reason it had stopped recognising plug ins when I opened old sessions or presets.

I therefore decided to delete the Application and reinstall... BAAAAAD mistake!

I put the original DVD back in and first I got a message about alias and the thing unable to start, then I finally got the install to start and after 2 hours I got the attached message of failed installiing. Now I'm royally ****** off and unable to use my program.

Any suggestions?