Commented Unassigned: Animated gif generating [1378]

I can't really understand, why gif animation isn't working without this?
```
//Optionally reduce colors
QuantizeSettings settings = new QuantizeSettings { Colors = 256 };
collection.Quantize(settings);

// Optionally optimize the images (images should have the same size).
collection.Optimize();
```
2 png frames, same size. Without code above it creates gif with only 1 frame. With code above, everything is fine. Is it a bug of reature?
Comments: Can you reply to my questions? Otherwise I will have to close this issue.