More tag, uploaded image and (possibly) duplicated content Issues

Hello, I’m having problems with “Pages with duplicate title tags” as Google Webmaster states about my blog

Let’s suppose I have a post with url

https://www.myblog.com/2008/05/23/some-unique-title/

In that post I write some brief text, upload one image (while checking the link to the post option) and use The More tag.

The image, no matter if I try to change the URL it point to, will always point to:

https://www.myblog.com/2008/05/23/some-unique-title/some-unique-title

It’s repeating post’s title!! and That’s why google webmaster tools is seeing duplicate title tag

both pages are not the same, the second (https://www.myblog.com/2008/05/23/some-unique-title/some-unique-title) shows only the image (but with smaller size :S ) and categorized under “no category”.

I don’t know what’s happening here. I’m thinking about modifiying wordpress code to make a 301 redirect to correct URLs.

Any hint?

Thanks.