The text window in the animation window where you setup your animations using collections. There's the text button that opens a text box above the "process" button right. Same thing with the search boxes in the collection or animation window. I've tried in a new project and I can copy paste but not in my main project, that's the weird thing.
Unity 4.2.1f4
2dtoolkit 2.1 final + hotfix 1
Also, because I use javascript mainly and that 2dtoolkit, like many other plugins, don't respect the unity folder standard of being in the plugins/standard assets/editor folders, it's unusable unless the code in Plugins. So updating such plugins is a bit of a pain and risky to lose all connections to your scripts if you don't do it right.