Regression test added for the bug fix: 6301050 - sun/awt/image/GIFImageDecoder/InterlaceAnimationTest.java fails on the following PIT build:

java version "1.6.0-internal"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.6.0-internal-java2d_13_sep_2005_00_48-b00)
Java HotSpot(TM) Client VM (build 1.6.0-ea-b51, mixed mode)

This test is failing more frequently on WinXP than SolSparc10.

Looks like this is a regression test failure.
See the Comments section for more information.