have you tried downloading the windows PS driver? unzip it and use the .ppd file to add manually a printer with tha .ppd file?
I try to install the Xerox workcentre 4250 in linux. i downloaded the package XeroxLinuxi686xpxx_4.30.28.tgz and XeroxPrinterPkgXPXX_2009_11_11.tgz. I install boot whitout problem. I launch "xpadmin" and I add a new queue. when I want change any queue, i cant becose itsn't