damaged preferences file

I have Quark 6.5
When I tried to open a project I'm working on this morning,
I got a message box that said:

"The application preferences file is damaged.
Please remove it and relaunch QuarkXpress."

I don't know what this means, or what to do.
I do need to resume working as soon as possible,
I'm a graphic designer by trade.
Should I trash the whole application
and try re-installing it?

Can anyone help me. Thanks a lot.