Hi, I'm encountering the same problem as Faith (whose post was marked as resolved without further comment).
I have run the plugin multiple times, and confirmed that the new full image size has been created in my FTP. But the images in all of my posts are still the wrong size. (You can see here how my images are extending past the width set by the theme).
Is a feature of the plugin that the source links of the images will automatically update to the new size, or is this something I must update manually?
Basically, am I encountering a problem with updating links, or was this not a feature of the plugin to begin with?