First, I think that Ricoh has OSx drivers for all b&w models.
Second, the 10mbs problem is not the problem here, when you have the 10mbs problem, prints do eventually come out the just take forever.
Lastly. The problem you have is a "Postscript Error" When you get a PS error you can use this page to help you troubleshoot the problem. 90% of the time PS errors are caused by errors in the file. Another 5% are caused by problems transmitting the data to the printer and lastly 5% are our fault.
Unfortunately, the Error you are getting is "undefined", so that doesn't give us much to go on.
I ran a call just last week where an HP would print out a page but our Ricoh wouldn't. However it still turned out to be a font issue.
Try to troubleshoot the problem to the exact page that fails. then try to remove elements (images, fonts, etc) until you find the exact thing that is causing the print to fail. then Replace or re-save that element and trry to print again.