Using the method FormTreeControl.Select()

I have created a form with a FormTreeControl. It contains the tables and fields in  AX.

Instead of browsing down to f.ex. InventTable, I use the method FormTreeColtrol.Select() to jump write to it.

In the control window I do not see the treeItem, I have selected, but exactly the next. The treeItem showing InventTable is write over the top edge.

When I use til up-arrow, the control show me the item exactly over InventTable as the first item in the control (blue/selected) and InventTable write below.

Why doesn't the control show me the selected InventTable in the top of the control in the first place?

Thanks in advance.