It seems that with animated gifs, both 32bit and 64bit versions can lose the static [unchanged background] of the image when the window is resized.
As seen by loading the gif, and resizing the window. Afterwards, only the changes are displayed.
OS Name Microsoft Windows 7 Home Premium
Version 6.1.7601 Service Pack 1 Build 7601
System Type x64-based PC
Processor AMD Phenom(tm) II X4 965 Processor, 3400 Mhz, 4 Core(s), 4 Logical Processor(s)
BIOS Version/Date American Megatrends Inc. 0603, 3/12/2010
Hardware Abstraction Layer Version = "6.1.7601.23403"
As seen by loading the gif, and resizing the window. Afterwards, only the changes are displayed.
OS Name Microsoft Windows 7 Home Premium
Version 6.1.7601 Service Pack 1 Build 7601
System Type x64-based PC
Processor AMD Phenom(tm) II X4 965 Processor, 3400 Mhz, 4 Core(s), 4 Logical Processor(s)
BIOS Version/Date American Megatrends Inc. 0603, 3/12/2010
Hardware Abstraction Layer Version = "6.1.7601.23403"