Hi Sergio, thanks for taking the time to report a bug.
Can you include your entire /etc/mysql/my.cnf And also a listing of your datadir (usually /var/lib/mysql). I think the answer, since you have no innodb tables, is to rm /var/lib/mysql/ib*. I have tested the squeeze -> wheezy upgrade and it worked ok for me in the simple case of an empty database without any innodb tables, but perhaps your innodb tablespace was corrupted somehow.
-- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org