Dear Bert,
Thanks very much for your reply. I was also frustrated that I was not
able to create a small test case that reproduces the problem, hence my
plea for ideas of what could be triggering the problem.
Your example 'svn:mergeinfo' missing could be caused by older Subversion
clients that in some specific merge cases committed unmodified
properties as modified.
You nailed it!
The machine where I normally make the tags like the one in the example I
sent is at svn 1.6.
I just tested, and when I tag with a v1.6 client, the svnadmin dumps
differ between the original and mirror, while when I tag with a v1.8.4
client, the svnadmin dumps are identical.
NICE!
Thanks very much,
--dustin