3
Usually you get this error if your installation was not successful in the 1st attempt.
In such case just login to your database (using phpMyAdmin or any such tool). Delete all table for that module. ( you can check the list of table in the module SQL script.)
Thats all you need to get rid of this installation error. (The other option is to add a delete command on the SQL script but I would not recommend that).
Hope this helps.
Deepak
A member of www.AquariumHomeCare.com