[Plugin: NextGEN Gallery] slideshow and JW Imagerotator 3.17

I have found NextGen a very fine gallery plugin. I switched gallery2 for it and love the options aand flexibility.
However, I found that with -all- thumbnail size options, the picures are -NOT- shown in the right format. Vertical pictures are not shown with the right dimensions but are cut off at the top (like the thumbnails are).
I guess this is something with JW Imagerotator. In the NextGen options menu I can choose to strech pictures to the right format, but this does not work. It is a pity that the slideshow option does not honor the dimensions of the real pictures…
Am I overlooking something, or is this a know issue (shortcoming)? Is this worked on? I do hope so.