I tested it on all Android versions with the emulator, it works perfect on all versions except 4.0. I also tested it on a Xperia U with 4.0.4 and Galaxy Nexus with 4.2.1.
The problem can be reproduced creating a new project with the ADT 21 assistant, with default options and changing the "Hello World" TextView with the AutoFitTextView:
I tested it on all Android versions with the emulator, it works perfect on all versions except 4.0. I also tested it on a Xperia U with 4.0.4 and Galaxy Nexus with 4.2.1.
The problem can be reproduced creating a new project with the ADT 21 assistant, with default options and changing the "Hello World" TextView with the AutoFitTextView: