I think it's a bug...

Saving to gif is problematic with effect layers (6)

Tile Map - Some Tiles not placeable (5)

Weird pen bug with display tablet (4)

Freehand pickup single click no longer works (2)

Issue With Eraser Tool / Alpha (2)

Gif shows incorrect palette (5)

Weird bug regarding brush freeform transform (4)

Brush->Make single color reverts to previous primary color (3)

All black colors become transparent (2)

Tips: Missing Text (trivial) (1)

Tile Map TMX export fails to specify renderorder attribute of <map> element (3)

Palette conversion bug (20)

Collection of Small Bugs and Useability Problems (4)

Grid layer always made visible (3)

Palette does not save properly (2)

Issue with colors (2)

Steam version freezing on start up (3)

A couple of minor things (5)

Animation playback problems (4)

Transparency bug (2)

Translucent paint mode behaviour (2)

Еrror when starting "Light table settings" (7)

Panning with space and my laptop's track pad (6)

File > Load Image > Quantize Colors > Number of Colors doesn't work? (6)

Brush Width Slider Problem (6)

Undo / Move Color (11)

When I copy a color and then edit it, it modifies the staturation (3)

When editing Modify/Create Tiles Sync Mode it doesnt update two next tiles (2)

Problem with selection and fill-tool (2)

Unselect 2x2 pixel brush not working (2)