sometimes, a ref generates "cite error", e.g., when you use "name="xxx" with an empty ref, but there is no "real" ref with this name.
it would be useful to be able to find all pages with such errors.
mw contains a mechanism to track such things, called Special:TrackingCategories. there may be a better way to find all pages with cite errors - i'll be happy to learn.
if no such way exists, i suggest to track those through the special page meant for it.
peace.