After publishing my last article, I found out an interesting thing about the edit control on a Windows Mobile 2003 Pocket PC device: the up and down arrow keys behave differently from the edit control in Windows Mobile 5. In WM5, the single line edit control responds to the up and down navigation keys by setting the focus to the parent window. When this happens, the parent window receives the corresponding WM_KEYUP messages and thus is able to set up a navigation mechanism. Not so with the Windows Mobile 2003 edit control. This version of the control seems to "eat" these messages so the parent has no clue about the requested user navigation. This became quite apparent on my implementation of the CFormListCtrl: the navigation would not work.
This problem was quickly solved by adding the OnKeyDown message handler to the CCeEdit class and forcing the control to set the focus to the parent window whenever an up or down navigation keys are detected. Voilá!