ToolTip usage in PB 11.5

Hi there

I try to use tooltip for a dw-column but can't get it work.

Step-1: Dw-column selected>ToolTip.Tab>Enabled> Checked that's it.

Step-2: Put some logic in an user-event ue_mousemove>Event ID = pbm_dwnmousemove

Here's the code: Please refer attached file

The code is debugged and no problem detected. The var's are significant and

return_string from Modify-instruction is empty string = OK.

In run-time there is a flickering when hovering over the column but no tooltip show up.

Step-3: Set the script in 'commented-mode'  and put some text in DW>ToolTip.Tip>Expression-box

             Now the ToolTip work's but not way I want it.

I would highly appreciate any efforts due to this problem from an other PB 11.5-developer.

Thank's in advance and

Best Regards from

Outi Vihko