Tooltips on a User Control

We have written our own user control - particularly nice for database centred input (a label and text/combo field with buttons etc.).

Once again though, as soon as we came to test we found a drawback - no tooltip. In fact, though hours had been spent adding the tooltips they just didn't work.

To be more precise - they did, but only on the user control if it's area wasn't covered by one of it's internal controls. In other words the tooltip wasn't adding the hooks in to the contained controls.

We didn't find a solution to this - anyone else know? The workaround was to copy all tooltips into a tooltip 'hosted' on the user control itself. This works but...