Subversion 1.2.3 fails during large add with: svn: '...../.svn' is not a directory

Has anyone seen this kind of error before?

Trying to add Xerces 2.7.0 downloaded from here [xml.apache.org] and
I get the following error when it gets about half way through the add
(around 2000 files of 4800 or so):

A xerces-c-src_2_7_0/doc/html/releases_plan.html
subversion/libsvn_wc/adm_files.c:837: (apr_err=20)
svn: 'xerces-c-src_2_7_0/doc/html/resources/.svn' is not a directory

Doing an svn status | wc -l shows that it added around 2200 files, of
the 4800 or so in total in the tree.

Steps to reproduce:

     * Download xerces-c-current.tar.gz
     * Unpack in your working directory:
         tar xzvf /tmp/xerces-c-current.tar.gz
     * Add to svn:
         svn add xerces-c-src_2_7_0

This is on Mac OS X 10.4.2, running Subversion 1.2.3 that I
downloaded from Metissian.

svn, version 1.2.3 (r15833)
    compiled Aug 27 2005, 06:13:54

Thanks for any insight!
Received on Wed Sep 21 11:22:35 2005