I put in three different item, numbers, and all three say the same thing. Incorrect item number.

Hello Joshua,
Thank you for your question about the 'incorrect item number' error. If you are receiving an "incorrect item number" error, it probably means you need to re-authorize. Just go to BidSlammer Preferences and on the first tab, click the "Refresh your Authorization" link. Once this is done, you should be good to go.
If the above does not resolve your issue, please let us know, and we can take the next step. Thank you for taking the time to write in.