Besides physical size there is also a size that depends on how many pictures are in the gif and how many colors are in the gif, yours had 32 kb and the limit is 19 for regular members. I have a program that optimizes the gif, and I got yours under the limit. Actually you didn't make it exactly square, it's 67 x 75 pixels.
Here's the one I optimized, but it's really hard to see the names.
http://www.yorkietalk.com/forums/att...1&d=1334192145