Correction !!
The function to generate the featured image for a standard post and an image post use the same values for the width and height parameter. The only difference is that the HEIGHT for the featured image in a standard post is limited when selecting the hardcropping option of the theme. Otherwise the HEIGHT is infinite (ok, not really, but a HIGH number).
If the hardcropping is off the functions generate the same native featured image. The style is a different story and can be adjusted in the CSS if necessary.
Sorry for the confusion. Still works as designed and I hope I got it right this time 🙂
Cheers,
Alexander @ http://www.mouseclick.com