Thanks, that worked. For anyone who runs into this, here's the corrected code (at least for this circumstance):

        private void link_MouseHover( object sender, EventArgs e ) {
            var lbl = (UltraFormattedLinkLabel) sender;
            var ui = lbl.UIElement.GetDescendant( typeof( FormattedLinkEmbeddableUIElement ) ) as FormattedLinkEmbeddableUIElement;
            if( ui == null || ui.IsDataFullyVisible )
                return;
            var tt = new ToolTip( lbl ) {
                                            DisplayStyle = ToolTipDisplayStyle.BalloonTip,
                                            ToolTipText = lbl.Value.ToString( )
                                        };
            var loc = lbl.Parent.PointToScreen( lbl.Location );
             tt.Show( new Point( loc.X, loc.Y ) );
        }

Oh, misread that part.  My test was also set too high if I used the DockableWindow (without adding the Height to the y-coordinate).  If I used lbl.Parent.PointToScreen(lbl.Location) and used the result directly, the tooltip was displayed correctly:

var loc = lbl.Parent.PointToScreen(lbl.Location);
tt.Show(new Point(loc.X, loc.Y));

-Matt

The screen shot in my last response shows it without the label's height being added to the y-coordinate, and it's still too high. Adding the y-coordinate is what I did on the simple form I copied it from, so the tool tip notification popped up below the control.

The x-coordinate that you're passing in is where the label begins, so I would think that it's correct that it's shown to the left of the 9; if you want it to be positioned farther to the right, you would have to adjust the x position accordingly.  

I also just noticed something with your code that I hadn't noticed initially: you're adding the height of the label to the y-coordinate of the location you're showing the ToolTip.  Without doing this, my initial suggestion of lbl.Parent.PointToScreen(lbl.Location) works.

-Matt