[dider]

Originally Posted by kacir

You have probably copied a quote at the end of the filename and quote " is [sometimes] encoded as %22 when it is a part of URL, so instead of http://example.com/"foobar" you use http://example.com/%22foobar%22

http://www.w3schools.com/tags/ref_urlencode.asp
http://en.wikipedia.org/wiki/Help:URL

The file wasn't created or edited manually though (at least not intentionally). I've never fiddled manually with the files on my Kindle, especially not with their names or extensions.

Neither was it sent via "send to kindle" function, as I get "The following document could not be delivered to the Kindle" message when I try to do it now.

And what about that semicolon? You may not have noticed that, but there's a semicolon in the extension - it seems like some badly written script could do that...