Im going to assume you have checked your theme and plugins are not the issue here? deleting old articles would not effect the issue at all. your web guy is either passing the buck, or full of BS. one of my websites is a news website and unless you have way too many aricles (in excess of a few thousand) this shouldnt be happening. I would suggest looking into whether or not category selection or the actual plugin itself is doing this. for better help, you might need to me more specific.
