In summary the cause was the use of “hidden texts” and the hidden texts were all valid keywords used in the old way.
The situation is really unfair for such an innocent action and it was back in 2007
As you know the main page of Rocks Off (the website) is this one

Back in 1999 below that image I added some hidden texts based in the old way to reach the search engines like Altavista and the old Google, the hidden texts were all 110% valid keywords, specifically they were “Rolling Stones, Mick Jagger, Keith Ricjards, Brian Jones, Ian Stewart, Stu, Bill Wyman, Charlie Watts, Mick Taylor, Ronnie Wood, Ron Wood, Nicky Hopkins, Merry Clayton…” (check Keith Richards spelling LOL)
Hidden texts are used sometimes by webmasters to reach public searching for very popular keywords like “Justin Bieber, Lady Gaga, Obama, etc) and then find a porno website or cheap stores but that was not our case, all our keywords were part of the content but the main page is only a picture.
So on September 7, 2007 we received the following letter from Google

Immediately, the very same day, we removed the hidden texts and filled the reconsideration request form, we were NOT removed from Google indexes and were reachable by Google until some months later when we were removed
We double checked the whole website to see if more hidden text were left but no, we didn't leave any, then I sent another resubmit request and the people at Google told me to “verify and index” the website (procedures used by Google since 2007 to ease the searching features.
We verified the website and it was OK by Google, the site was verified by them and it’s real but when trying to index the website we get the message
“General HTTP error: HTTP 403 error (Forbidden)”; we have requested to be reconsidered several times and the answer is always the same
“We received a request from a site owner to reconsider how we index the following site: http://rocksoff.org/.
We've now reviewed your site. When we review a site, we check to see if it's in violation of our Webmaster Guidelines. If we don't find any problems, we'll reconsider our indexing of your site. If your site still doesn't appear in our search results, check our Help Center for steps you can take.” So they have never ever checked that the problem is that it was punished and is forbidden, the answer is always the same since 2008, one time I was in contact with a nice lady at Google in Ireland but after a couple of e-mails she disappeared and since then the answers are all the same
We now are going to send a new reconsideration request, explaining in more detail and with a first paragraph summarizing the situation and be very clear about the problem, it’s not index and/or verification processes… we are forbidden to index our own website
BTW, all other search engines reach us.
If anyone can help to solve this problem, please do it, on one way to be isolated is fine as we are not reachable by many board spammers but a lot and I mean a lot of information on both, the website and the message boards are unreachable by those who only use Google (the number one search engine)