Long filenames on a sharepoint not possible

Why is it that long filenames are not permitted on a sharepoint? If I create a file or directory on a mounted sharepoint, I am limited to 31 characters. I haven't been able to find any KB article that addresses this issue. OS X Server 10.2.8, OS X client 10.2.8 (I am sure this *bug* affects all vintages of server and client).