Blue Screen Caused by sfmsrv.sys

Hi all,

I'm running Win2003 server standard with SP1 installed.
My system is blue screening fairly regularly, with the cause being
sfmsrv.sys and page_fault_in_nonpaged_area. As I understand it, sfmsrv.sys is
the Appletalk protocol driver.
I've uninstalled services for macintosh as a temp possible fix, but we need
to run this service for our MAC users to access files on this particular
server.
Any ideas as to why this might be happening?
Thanks.