I have tried your suggestion but it does not solve the problem. I've binded the function to F3. After the problem appears , I press F3, the selection is repositioned at root(my 0 Is \) but, after this , the problem persist : pressing 5 up_key the cursor goes up 3 Times and down 2 Times(really strange...).
Comment on Re^2: Cursor keys with Tk::Hlist goes wrong
You can find all the code (with your suggestion) at https://sourceforge.net/projects/copyandverify/files/ver0.010_ReplByDate/ .
At the moment, the linux version has the itemcreate for col 0 commented and the add (with all attributes) active, so it works.
If you search a line with all # you find the problematic code and your suggestion (on F3).