The Scope Item Count gives an approximate number of items matching the scope. However at one of my customers it showed only six items for their entire file share !?
There were no Crawl Rules and the Crawl Logs showed tens of thousands of successfully crawled items so what could be wrong ? I played with the scope rules (recreated them, inverse logic, etc) but no luck. I opened up Reflector on the Scope Count property to find that it is calculated through a Search Query. Then it hit me that the account I logged in to to perform Search Administration was a local account that didn’t have access to the file share, thus the Query for returning Scope Count would security trim those results for me.
I’d expect any SharePoint Administrator to get a correct count of items in the Scope so this seems like a minor design flaw to me.