g1smd - 10:06 am on Jun 30, 2013 (gmt 0)
Run Xenu LinkSleuth over the site and check for errors.
Also construct a text file list of "good" and "bad" URLs. Duplicate the whole lot for both non-www and www versions. In LinkSleuth set the scan depth to the lowest possible then import that list of URLs and check you get the right results.