Mirror sync problem

Hi,

I've started to sync a mirror and received this error in return :

# svnsync sync http://repos.com --username user --password pass
Transmitting file data .svnsync: Server sent unexpected return value
(500 Internal Server Error) in response to MKCOL request for
'/!svn/wrk/b78fe308-e3eb-de11-9c3d-003048d7387c/conf'

I tried twice and the sync stopped each time at r1796 (to be exact,
while transmitting data from r1796).

I veiwed the logs and saw that files (/conf, /db, /format, /hook,
/locks, folders and files) have been commited. I asked the user and he
said he made a mistake with Tortoise. He created a repo inside his
working copy and comitted it, the exact procedure is obscure as it was
in April 2009.

The repository works fine actually, but svnsync refuses to sync.

How can I bypass this particular revision ?
I thought to definetly remove the revision, I did it for some reason on
another repo, but I wished an expert advice : does a revision removal
will create a problem with the svnsync tool ?
The previous repo I removed a revision from will be concerned also, and
now that this problem appeared I'm afraid of the flexibility of the
svnsync tool.

Thanks in advance,

-- 
Bastien Semene
Administrateur Réseau & Système
admin_at_cyanide-studio.com
+33 (0)1 47 86 30 80
Cyanide S.A.
5, Boulevard des Bouvets
92000 Nanterre - FRANCE