I've use this software a LOT over the past six or seven years.
The lastest two versions of PDF Creator will not create readable PDF files from images created by Dell All In One Center printer software. One scans a document with the printer using the Dell All In One Center software; the result is a picture image in bit map format. I've been reducing the size of the image to 80% to get a letter-size image that will fit on a single page when PDF Creator creates a new document.
Also, having similar problems on an intermittent basis printing Yahoo email traffic into PDF files.
The PDF Creator software process DOES complete but Adobe Reader cannot read the resulting file created by PDF Creator.
This could be something added to the Adobe software intentionally as a marketing ploy to keep its sales of Adobe Acrobat from slipping away.