How do I use an infopath 2007 multi-entry list box with sharepoint?

Hello,

I am creating my first form (hurray) in infopath. Due to my company's sharepoint implementation, the form must be filled out in infopath and not in the browser, just as background.

I need to use a control that lists various options that user can select from, but they need to be able to select one... or none... or some... or all of the options.

Normally (in most systems) there are comboboxes that seem to allow this...but infopath apparently uses a rendition of that with checkboxes.

That's fine, I suppose, it just kills shift- and ctrl- click functionality.   But anyways - when I save my data to a sharepoint document library (as a content type)...  the field/column with multiple selections ends up blank.

Any hints on how to fix this... or what I'm doing wrong?

Thanks