Something is fishy with the Grunt runner

Hi there,
I get an error from grunt plugins trying to do "fancy" stuff in the console window using calls to the process.stdout ala:
            process.stdout.clearLine();
            process.stdout.cursorTo(0);

The error : Warning: Object #<Socket> has no method 'clearLine'

Try the png2svg grunt plugin for an example of this error.

Running the plugins from the commandline works as expected.

Any thoughts on this?