Hi Ryo-ohki, thanks for your reply.
Regarding your question,
I tried both things. The first was trying to access the webdav directory through the .php script provided by ownCloud (it's supposed to keep you from managing all the webdav stuff). This attempt gave me the kind of errors I mentioned above.
I also tested the other way. In this case, trying to access the ./data directory inside owncloud gives a 403 error and no dialog box to enter user/pass. Trying to access via finder, an error message urges me to verify the IP address or contact my sysadmin
Ok, i'll keep trying different things today, and i come to something useful will put it here for it may be useful to someone in the future
Ninja edit to ADD
Trying to access the php script directly through a web browser prompts my with a log-in dialog, to no success. It is not sending the auth info and so it gets back to the initial point (log-ind dialog) in a loop that ends when you get a bit bored and press CANCEL. Then, you receive an XML file:
No basic authentication headers were found