I make use of statistics provided by google to many of my sites.. It shows sometimes really important info, like errors on crawling and so on. But! For some of the sites I can't verify my ownership - these sites have dynamically generated URLs but there I've implemented mod_rewrite and special google file (that is blank actually) shows in a browser. But while making a verification I keep getting an error: "NOT VERIFIED
We've detected that your 404 (file not found) error page returns a status of 200 (OK) in the header."
What should I do?