highlighting Form Fields

In ATA / Style Forms I have set "Highlight Form Fields" to Yes. I noticed (used firebug) that "class= highlight" gets appended when a textarea has focus, but that this does not take place for single line input fields. So, highlighting only works for textareas, and not for single line input fields.

Is this a bug in Atahualpa? Or should I check the plugin FS Contact Form, which I use for this form?

I just checked: Submit Buttons: Hover Style and that doesn't seem to work either. Is this a different problem? And what is causing it?