PDFGrabber exists to grab .pdfs generated to the desktop by Acrobat Distiller. Microsoft Excel, and perhaps other apps, incorrectly generate separate print jobs for each page, all with the same name, thus overwriting the previous page. PDFGrabber grabs the pages and accumulates them elsewhere by file name until the Adobe PDF "printer" spool is empty, at which time it merges all grabbed pages. Single page documents will simply be put back on the desktop.
PDFGrabber ReadMe available here.