Microsoft explains the problem well on the link below.
I used the solution described in that Microsoft bulletin to resolve the problem of print jobs being rendered to JetPCL Document Capture as if it were text instead of binary/RAW PCL data.
It took me a bit to get the problem straight in my head. You did a good job of demonstrating it to me on Friday afternoon. In the back of my mind I thought that something like that was going on. But I couldn’t wrap my head around it until I talked to you.
It only took about five minutes of research to find that bulletin and after some testing it appears to be the answer to the problem. I created and set the registry value as described and now that JetPCL Document Capture is receiving proper data and it is working beautifully.
However, I believe the above solution affects how all LPR jobs are handled by all printers on that computer.