After updating to Mac OS X 10.4.6 or later, Apple File Service (AFP) share points from Mac OS X 10.3.9 servers may be mounted read only.
This can occur if the volume originated from an AppleShare IP migration, and the AppleShare IP administrator had selected the "Can't move, rename, or delete this item (locked)" option, which set the user immutable flag on the share point. The AFP client in Mac OS X 10.4 to 10.4.5 ignored this flag, but that is no longer the case, so some share points may appear read only.
To change the Finder flags using a 10.4.6 or later client:
server:/Shared Items admin$ ls -lo total 112 drwxrwxr-x 2 root admin uchg 68 Sep 9 2005 Public drwxr-xr-x 2 admin admin - 68 Jun 5 14:02 Public2 server:/Shared Items admin$