Strange diff behavior on branch

[Lemke, Michael IZ/HZA-IC1]

I have a file that was initially added on a branch.  If I
do a diff based on a date I get this:

$ cvs diff -D 16-jul-2003  koucopy.sh
cvs diff: koucopy.sh is a new entry, no comparison available
$ cvs stat koucopy.sh
===================================================================
File: koucopy.sh        Status: Up-to-date

   Working revision:    1.1.2.12        Mon Jul 21 05:48:12 2003
   Repository revision: 1.1.2.12        
/mnt/bflow/cvs/repos/inacom/Attic/koucopy.sh,v
   Sticky Tag:          B_PROD (branch: 1.1.2)
   Sticky Date:         (none)
   Sticky Options:      (none)
$ cvs log koucopy.sh

RCS file: /mnt/bflow/cvs/repos/inacom/Attic/koucopy.sh,v
Working file: koucopy.sh
head: 1.1
branch:
locks: strict
access list:
symbolic names:
        B_PROD: 1.1.0.2
keyword substitution: kv
total revisions: 13;    selected revisions: 13
description:
----------------------------
revision 1.1
date: 2002/12/13 14:08:29;  author: bflowadm;  state: dead;
branches:  1.1.2;
file koucopy.sh was initially added on branch B_PROD.
----------------------------
revision 1.1.2.12
date: 2003/07/21 05:48:12;  author: bflowadm;  state: Exp;  lines: +5 -2
...
$ cvs -v

Concurrent Versions System (CVS) 1.12.1 (client/server)



Is this expected behavior?  Diffs on revisions (-r 1.1.2.10) work.

Thanks,
Michael