Difference between LPR and remote IPP job

[Carlos Rodrigues]

I'm having a problem with windows clients printing to a shared printer on my Mac, which is totally baffling me, so I have a (not so) simple question...

What's the difference between a job submitted by lpr and a job submitted remotely over IPP by a windows client?

Does a remotely submitted job get additional processing over a local one? If so, where can I change options or see what this additional processing is doing?

See, my problem is: if I print something from a windows client to the shared printer, the margins come out all wrong(*). But if I "print to file" on the windows client, and then print the resulting .ps file on the Mac using the "lpr" command, it comes out just fine...

(*) More specifically, a job sumitted as A4 seems to be scaled to the Letter size, thus ending up too big for the physical media width (Letter is wider than A4) and with the top cropped (Letter is shorter than A4). Even though the default paper for the printer is set to A4 in both the web interface and the windows clients.