2.1.0-pre1 upgrade warnings

I've recently upgraded drupal from 4.6.6 to 4.7. I disabled spam before upgrading drupal, then once 4.7 was ok I uploaded the 2.1.0-pre1 version of spam. When I enabled it, the drupal screen showed a bunch of red warning messages, text below. Is it a bug? I ended up dropping the tables and reinstalling a new copy of the spam module to be on the safe side.

Or if those messages are harmless it would be good to add a note in the docs to say they can be ignored.

Cheers, MrB

user warning: Table 'spam_tracker' already exists query: CREATE TABLE spam_tracker ( sid int(11) unsigned NOT NULL auto_increment, source varchar(64) NOT NULL default '', # node, comment, trackback, etc... id int(11) unsigned NOT NULL default '0', probability int(2) unsigned default '0', hostname varchar(128) NOT NULL default '', # source IP hash char(32) NOT NULL default '', timestamp int(11) unsigned default '0', PRIMARY KEY sid (sid), KEY id (id), KEY probability (probability), KEY source (source), KEY hostname (hostname), KEY hash (hash) ) TYPE=MyISAM /*!40100 DEFAULT CHARACTER SET utf8 */; in /home/batgung/public_html/drupal47/includes/database.mysql.inc on line 120.
user warning: Table 'spam_tokens' already exists query: CREATE TABLE spam_tokens ( tid int(10) unsigned NOT NULL auto_increment, token varchar(255) NOT NULL default '', spam int(10) unsigned default '0', notspam int(10) unsigned default '0', probability int(10) unsigned default '0', last int(11) unsigned default '0', PRIMARY KEY tid (tid), UNIQUE KEY token (token), KEY spam (spam), KEY notspam (notspam), KEY probability (probability), KEY last (last) ) TYPE=MyISAM /*!40100 DEFAULT CHARACTER SET utf8 */; in /home/batgung/public_html/drupal47/includes/database.mysql.inc on line 120.
user warning: Table 'spam_custom' already exists query: CREATE TABLE spam_custom ( scid int(10) unsigned NOT NULL auto_increment, filter varchar(255) NOT NULL default '', style int(2) unsigned default '0', # text, regex, URL effect int(2) unsigned default '0', action tinyint(2) unsigned default '0', matches int(11) unsigned default '0', last int(11) unsigned default '0', PRIMARY KEY scid (scid), KEY filter (filter), KEY matches (matches), KEY last (last) ) TYPE=MyISAM /*!40100 DEFAULT CHARACTER SET utf8 */; in /home/batgung/public_html/drupal47/includes/database.mysql.inc on line 120.
user warning: Table 'spam_log' already exists query: CREATE TABLE spam_log ( sid int(11) unsigned NOT NULL auto_increment, source varchar(64) NOT NULL default '', # node, comment, trackback, etc... id int(11) unsigned NOT NULL default '0', uid int(10) unsigned NOT NULL default '0', hostname varchar(128) NOT NULL default '', # source IP entry varchar(255) NOT NULL default '', timestamp int(11) unsigned default '0', PRIMARY KEY sid (sid), KEY source (source), KEY id (id), KEY timestamp (timestamp) ) TYPE=MyISAM /*!40100 DEFAULT CHARACTER SET utf8 */; in /home/batgung/public_html/drupal47/includes/database.mysql.inc on line 120.