Sliced Image and transparent borders

Sliced sprites and transparent border don't seem to work well together. Whenever I have a transparent border at any side the image is displayed completely wrong.

The correct view, a sliced sprite with no full transparency at any side:
This is also an image: white on white( )

Now, if I delete all the pixels at the left border, this results in drawing the sliced sprite wrong:
This is also an image: white on white( )

Now to make it even worse, I could delete all pixels at any side, and this results in the following:



Would this be a problem from Unity itself, or should I fix it myself by trimming all images and adding borders in code? This however would be quite a time consuming work to get right. Since padding layout doesn't have float support, I can't use that either.