In the readme.txt file, consider changing the line

UPDATE SYSTEM SET weight = 10 WHERE name = "workflow"

to

UPDATE system SET weight = 10 WHERE name = "workflow"

because table names can be case sensitive depending on the server OS and the settings. See

http://dev.mysql.com/doc/refman/5.0/en/name-case-sensitivity.html

Someone already encountered a problem with this in

http://drupal.org/node/97268