Hi Don, you're right. There's an error in the type definition of the timezone column. You can fix it by running this SQL in your database:
ALTER TABLE `og_contacts` MODIFY COLUMN `timezone` float(3,1) NOT NULL default '0.0';
ALTER TABLE `og_companies` MODIFY COLUMN `timezone` float(3,1) NOT NULL default '0.0';
ALTER TABLE `og_users` MODIFY COLUMN `timezone` float(3,1) NOT NULL default '0.0';
Note that you may need to change the prefix 'og_' if you chose another one for your installation.
This will be fixed in version 1.2.
Thanks.