I could not find an Ashell 5.1 Fourm so I decided heres a good bet..
I've not noticed this before so it could of been in the latest updates from 5.0 to 5.1 or even TER15.DLL, but not 100%, from what I can see my grouping XTree lines are, well, not complete as your seen by the image below.
(If running ATE 5.1 and Ashell/AIX 5.0 (what I am) will cause this forget this post and books some Grenada flight tickets instead)
Nothing important, just thought i'll point it out, if no one else can emulate it, it must be my setup/install.