Our newest content wiki, the Neapolitan Wikisource, just (presumably) had its stats recounted on August 1st, for the first time since it was created and its content was imported. The "content pages" count dropped from 10,167 the previous day to 413. The reason I am opening this task is not the drop itself (which is large but not unprecedented for new wikis) but the count that it dropped to.
413 content pages is 230 pages higher than the total number of non-redirects in the main namspace (183).
(The main namespace is the wiki's only content namespace and the wiki uses the default 'link' counting method.)
How is this possible? How could it be fixed? Am I missing something here that makes this actually not an error?