i don't think Mods ban mac addresses. not unless they have packet sniffers or any tools that could sniff your laptop's local area adapter's mac address.
i simply think it's the ip address that was banned.
deleting cookies won't help either ( that is another story) since the message he got was "he was banned from the forum".
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there are members that are already banned. maybe one of the IP range similar to yours (alainphillip ) has been banned. The best thing you should do is to send PM to the mods. they could compare from their ban list the banned IP to your own IP.
just a thought.