Which files are used to print?

I was just looking at my newest book on Lulu. The cover icon is showing the names at the bottom warped. I went into the project and it showed a link for both source and pdf ready files. The source files show the names perfect. The print ready cover file though shows it crooked. Like the last names had been warped or something. This doesn't show in my copy of cover file either. I contacted them but my proof is already been ordered and I'm hoping it's using the good file.