Some GIF images cannot be loaded when scaling is applied

Run attached code sample and follow the next instructions. That is compatibility test, that started to fail, beggining from b12.

Objectives:
This testcase aims at testing the image cursor feature. Typically, the following scenarios are covered -
getBestSize() called with 2 different sizes, one lesser than the platform size and another larger than platform size.
getMaximumColors()
Invalid main image URL and a valid placeholder image is used to see if the given hotspot values are clamped to the size of placeholder image.

User Interaction:
- Hover the mouse on each of the buttons and check if the following cursors are shown
A bug image on button 19, 19
A giraffe image on button 299, 299
A tiger image on button 290, 290.

A bug and a tiger are not shown for some reason.