What's the best way go go about removing bad products?

I'm helping a buddy of mine upgrade his site, and he has a few old products installed that don't have table entries anymore. I get errors like this:

Invalid SQL:
SELECT TITLE FROM `vb3_cron` WHERE TITLE LIKE 'AboutToday';

MySQL Error : Unknown column 'TITLE' in 'field list'
Error Number : 1054
Request Date : Sunday, June 8th 2008 @ 11:01:46 AM

And this:

Database error in vBulletin 3.7.1:

Invalid SQL:
ALTER TABLE vb3_post DROP nowplaying;

MySQL Error : Can't DROP 'nowplaying'; check that column/key exists
Error Number : 1091
Request Date : Sunday, June 8th 2008 @ 11:03:00 AM

The products are disabled, but seeing them in the list and knowing that they're there is bothering me.