Konica-Minolta 4750en crashed using CUPS 1.52 but not 1.50

Hi

I just updates my Ubuntu desktop to 12.04 (fresh install rather than upgrade).  ON reinstalling my printers from the cups web interface I found that the 4750en although found and installed by CUPS using the same ppd file (from K-M support site) any job sent to the printer from cups 1.52 hangs the printer (flashing processing light and the printers web interface becomes unreachable).  I have tried installing as a jet/direct or ipp printer to no avail.  Also tried installing via USB with the smae results.

I have a laptop with cups 1.50 (on ubuntu 11.10) installed and this prints fine over ethernet using either jet/direct or ipp protocols.

I am currently trying to find a way to print to file from the 2 cups versions so that I can compare the PS output for any clues but can't see a way to do that? If the problem is malformed postscript can I send a .pdf to the printer from the shell to bypass the interpreter?

any help much appreciated

Mark