OK, I give up with SVN.
Apparently all of the effort I put into the system yesterday and last
night is broken.
I copied correct versions of the jpg files (which were broken).
I marked several hundred files as 'binary', including these jpg files.
I committed all of the changes.
The commit succeeded.
Due to a lock problem here I removed all of the svn directory.
Then I did an svn checkout to re-fetch the tree.
It appears that the work I did was lost even though the commit succeeded.
For example, try
firefox axiom30yr.jpg
which should be a picture of a bayou. The picture is broken. Still.
Even though I explicitly copied a correct version, marked the new
version with svn tags, and had a confirmed commit.
SVN is clearly not ready for prime time.
t