Exposed filters do not submit on 'keyup' event

I created an Entity Reference View Widget for a custom CCK type and added an exposed 'contains' filter on title. I have the exposed form set to 'Entity Reference View Widget' and autosubmit. In my form when I enter text in the filter nothing happens until I navigate away from the text field causing a 'change' event which works as expected, trigger an ajax request to re populate the view. However I expect this to also be triggered as the user types. No log messages are generated in my console.