I did briefly search to c if this was reported, and possibly it hasn't,
When I select Edit > Set selection ratio > same as image, the slection box jumps to vertical when I drag the cursor on the image and I can't select a more horizontal shape, and thus the selection fails.
To reproduce:
- 1. Open image in Viewer and select Edit > Set selection ratio > same as image
2. click and drag on image
3. cannot drag select entire image because the rectangle jumps vertical
4. select "Set selection ratio > same as image" again
5. selection jumps to correct ratio but only to the width of previous vertical rectangle
6. attempt to drag the rectangle to resize and it jumps vertical again
7. select another ratio
8. other ratio works with no fault
9. select "Set selection ratio > same as image" again
10. finally the "same as image" ratio works and can drag to fill the image, it does not jump vertical any more
11. thereafter changing between ratios there is no further problem with "same as image" ratio
below how it looks after doing no.2
0.61 on Debian Linux 64bit