>If you're able to get it working at all, you're ahead of me. The tips show up well enough, but selecting an item with tip active has erratic results for me. Are you sure you can select items with tips active perfectly?

Seemed to work OK with listbox. I think the bug is with ComboBox. From MSFT KB:

1.PRB: Combo Box ItemTips Prevents Selection and DisplayValue: When a combo box that has a narrow column width and ItemTips property is set to true (.T.), the ItemTips window prevents the selection of a choice from the list of values in the combo box.

2.PRB: ItemTips = .T. Causes Error When in Private DataSession: In Visual FoxPro 5.x, the Listbox control with the ItemTips property set to .T. - True causes a Cannot access the selected table error when the DataSession property of the Form is set to 2 - Private Data Session.