Sweet, a Mac issue I can troubleshoot! I haven't had any issues printing images of that size with my MacBook Pro (also with Snow Leopard) over my wired and wireless networks (both with Windows computers), so this kind of stumps me. My guess is that it's probably an issue with either CUPS or SAMBA on the Mac. I'm no expert with configuring CUPS manually (since everything's done for you through the Printer GUI in System Preferences), so let's try playing with SAMBA first. Most of the printer problems I've had with Macs on Windows networks usually has to do with either the computer the printer is being shared through (though, this doesn't like it applies to you since it sounds like the printer is hardwired to the network - please correct me if I'm wrong) or the workgroup the Mac is on (in my experience, Macs have never played well with workgroups). In your customer's Mac's System Preferences, check out the Network prefs, select the network interface you want to print over, then hit Advanced. Select the WINS tab from the window and make sure the workgroup is set to a common name across all of the Windows computers (and the printer, if it has an option for it). Give that a try and post back if there's no improvement. Cheers,