[Plugin: NextGEN Gallery] thumbnails not generated for square images

First of all, thanks for the excellent plugin.

I’ve come across a strange issue, the Edit Thumb feature does not appear to work on square aspect images. It failed to generate a thumbnail for an image at 512×512 ( sometimes the crosshair on the thumbnail UI would not even appear ), but when I resized the image and uploaded it, the thumbnail was generated fine.

Thanks,
Andrew.