In using your controls we've noticed the behavior when tabbing on a web from is not quite like the default beahior of most controls.
For example the multi-select control with checkboxes accepts the focus (it does not highlight) and pressing enter drops down the list. I haven't found any way to scroll through that list using arrows and then pressing enter to select a value.
I've had siilar issues with other controls. Date and Time will accept a focus and a down arrow will change the datepart but I can't tab off the control.
Is there a property setting I am missing?