There was an error opening this document. This file cannot be found

Recently, a co-worker of mine started using a vault that I had set-up a while ago.  He is getting the error "

There was an error opening this document. This file cannot be found" when he tries to check a drawing into the vault.  I have the vault set to auto-create a PDF at check-in, and I think the error has something to do with Adobe trying to open the PDF file at check-in.  Is there any way to prevent adobe from starting when checking drawings into the vault?

Thanks all,

Dan

SolidworksWorkgroup Pdm