sometimes it just doesn't work unfortunately on some sites i tried tried tried and couldn't get relevant content... others did instantly one thing is give Y a day as for some reason some sites take a day to show relevant ads.
I would suggest moving back to adsense for the site. This has happened on a few on my sites and never did resolve. I just assume that there are not that many advertises in the nich yet. Good luck...
Is your site a blog by any chance? When putting contextual ads on a blog, you have to go through the page and remove all references to anything blog-related. ANYTHING. At least in the beginning. Otherwise, all you'll get will be ads for blog services.