what are your settings for the gif format?
I've been saving with pretty much the default settings. Only thing I changed on the "Save for web" menu was the file form. Maybe try saving with default settings if they aren't already.-Selective
-Diffusion
Colors - 256
Dither - 100%
Transparency (checked)
Convert to SRGB (checked)
Quality - Billnear
Looping options - Forever
try unchecking transparency and set the quality to bicubic, that might help sometimes errors can be caused randomly by certain settings occasionally-Selective
-Diffusion
Colors - 256
Dither - 100%
Transparency (checked)
Convert to SRGB (checked)
Quality - Billnear
Looping options - Forever