lucy24 - 8:56 pm on Oct 20, 2012 (gmt 0)
You're fine. As with so many crawl "errors", g### is simply telling you that it found something that you may or may not have intended.
But do go back to your developer and have them replace the former 200 rewrite (or was it a 30x redirect?) with a 410. It sounds as if they just deleted a line of code instead.
Using 410 instead of 404 sends the message that you know the pages are missing, they're supposed to be missing, you removed them on purpose, and in a few years google will stop asking for them.