v.0.21(L) Previous/Next page on apng broken

[marsh]

1. View file.apng in tab
2. Stop animation
3. *Only the previous page icon is visible, and this makes screen go blank when used.

[xnview]

Please, could you test XnViewMP 0.25

[marsh]

Both previous/next icons are now visible.
Viewing the attached apng differs slightly from v.1.97. After frame 10 is shown, pressing "next page" will cause screen to be empty, but with v.1.97 going to next (frame isn't possible).