Check out the Lost Media Wiki’s article on the Curious George test pilot!!!
Before Curious George premiered in September 2006, there was a test pilot of Curious George that was screened to preschoolers in July 12, 2004. The test pilot was never seen; as it was only seen by preschoolers. It is never seen at all. But, some pictures and screencaps had an early version of Zeroes to Donuts, and the hugging image of the logo.
The logo from 2004.
An early beta of the episode Zeroes to Donuts, from 2004.
Update: so, previously, it was unknown if this actually exists or not, but I may have found evidence that this does exist, since this says Curious George in 2004: http://www.milowerx.com/wp-content/uploads/2014/08/Mike-Milo-resume-5-29-14.pdf