CComboBox problem

I have a dialog that I am adding a (CBS_DROPDOWN style) CComboBox to. I am using the dialog editor. When I place the CComboBox on the dialog it's edit control's size in 50 x 12. The dropdown list's size is 50 x 100. However, when I run the dialog, the combo box edit control's vertical size is about 2 or 3 - not 12. What's happening here?

Thanks,
Be_ginner