Hey everybody,
I know this thread is stale, but I have an update to the situation. First, a quick recap of the environment:

SLED-12 x64 (SP1, SP2) is hosting an HP Officejet 4215; initially, I had it configured using hpijs drivers only to discover that I needed hpcups to be able to really print to it, both locally and remotely. Locally, I could print anything, including PDF files. Remotely - my remote computer is Windows 7 SP1 x64 - I could print anything except PDF files (See previous error messages). Installed on the Windows 7 PC: Adobe Acrobat Reader.

I went so far as to uninstall SLED12 and try Leap 42.x, all the way up to 42.3 - same results as posted earlier. I finally opted to uninstall Adobe and reinstall - no change (I didn't expect any change, since I could print to Windows and OES printers without issue). Now, I opted to try a different PDF reader all together, leaving Adobe uninstalled. The reader is SumatraPDF. Lo and behold! I can print PDF files from the Windows 7 PC to the CUPS printer! I see a message in the error_log: [Client 18] Returning IPP client-error-bad-request for 0x401c (no URI) from <IP address - the address of the Windows 7 PC>. Outside of that, the problem is gone! Too weird...

I'm assuming this implies that Adobe doesn't know how to properly format a PDF for printing then??? Thoughts?