We are creating purchase orders with PPWAtch. PPImage creates and emails the pdf to our vendors. In a couple of instances they can view the pdf on the screen, but when they print it only blank sheets come out of the printer. The same pdf file opens and prints locally without a problem.

When you say:
"The same pdf file opens and prints locally without a problem." did you send yourself or put yourself as a CC on the email to make sure you have the exact same PDF file. If it is realy the same PDF then you must look at the environment where the print output does not work, else you need to realy get the same PDF.
I also find it bizarre that they can view the PDF, if this realy is the case your vendors need to ask there MIS to help troubleshoot.

Regards

It is the exact file. The purchasing agent sent me the same copy she sent the vendor.

I also find it strange that they can view it and not print it. This is happening with 2 different vendors at different locations.

Hello,

We generate PS code that is then converted into PDF format. Since the PDF can be viewed we know that the code and the conversion was successful.

Now, when you print a PDF there are many factors that come into play including the printer you are printing to and the printer driver. Unfortunatly, we do not have control over this. It is possible (but not certain) that just updating the printer driver could resolve this issue.