ponsting images and links on WP 2.1

Hi, after upgrade to 2.1, when posting any image to a post the image link is writed using single cote like <img src='http://mysite/..../file.jpg'> and on older versios was like <img src="http://mysite/..../file.jpg"> ?
This modification is making the Lightbox plugin not work, to fix you need to edit manualy the image link.

This should be a bug or is the new way that WP will use to code the links?

You can check this just showing the source code of any blog with an image or link posted. In firefox just click on the Show menu and them in Source-Code option.