Hugo, first thank you for your sustained help!
As mentioned before, I registered also directly from their mail-list-managing-site
http://xircles.codehaus.org/manage_email. And that was before I posted the last time (from nabble)...
Still weird, I posted once offtopic my problem directly from my email to the mail-list and it didn't get through...
The only configuration I changed on my subscription at xircles was, that I didn't want all the postings sent to my account; I intent to use the mail-list only through nabble, as I did it before...