Those are not database errors
vBulletin Installation/Integration Common Issues and Resolutions.
Maybe possibly you need to follow step 3 as you may have relative image links in your custom style. Something there is no profileblue in classifieds.
As far as your cookie thing you really need to disable plugins etc any non standard
vb things. You can test right here this is a clean
vb and classifieds not really used just a test. Keep note of the url as I dont list it on the site
Main Index - PhotoPost Classifieds
username testing
password photopost
You will see you most definately do not get logged out