How to stop LISP routine that plots to Adobe PDF from adding a .plt extension.

[mmartin]

I have a lisp routine that sends multiple pages to Adobe PDF. The lisp routine names the files (pages) as they are created. The extension given in the lisp routine is .pdf. However, once the file is created it's adding a .plt extension. Where would this come from and how can I stop it from happening? I've attached the lisp routine in case it helps. I've also attached a screenshot of the files that were created. 

[Sea-Haven]

It looks like something that is in the "Adobe pdf" try testing with " Dwg to PDF" you may need to check page size.