Hilary,
The date and time format settings are behaving strangely in my date/time picker control. After opening the properties for my control and selecting desired date format, the time format selection automatically goes to "(Do not display time)"; similarly, after selecting the desired time format, the date format selection automatically goes to "(Do not display date)". If you click "Ok" and reopen the date/time picker properties, only my date format selection shows; the time format selection still shows "(Do not display time)". Surprisingly, after viewing the form in preview mode, the control correctly displays the selected date in the desired format and the time is correctly displayed in the 24 hour time format. Do you observe the same behavior when modifying your date/time picker control properties?
By the way, do you know of a Microsoft page where I can view know bugs with InfoPath that Microsoft plans to fix?
Thanks,
~W