Quoting Ivan Sergio Borgonovo mail@webthatworks.it:
I cleared them in the update/insert hook_user
$edit['field']=NULL;
but I still get b:0; in the data field of the DB.
Uhm, b:0; is the value of a serialized NULL.
Earnie -- http://for-my-kids.com/ -- http://give-me-an-offer.com/