[Seaside] Odd inconsistency in Seaside One-Click 3.0.7

[Lawson English]

I was reviewing the Seaside book while refreshing my skills, and I 
noticed this very strange, trivial, but fundamental bug/inconsistency:

http://www.youtube.com/watch?v=2RyREN00Nok   (less than 2 minute demo).

The issue is hardly worth mentioning, except for totally new users, but  
I DO wonder what is going on that changes the behavior from the first 
right-click on the category pane to the second.

L

-- 
Squeak from the very start (introduction to Squeak and Pharo Smalltalk for the (almost) complete and compleate beginner).
https://www.youtube.com/playlist?list=PL6601A198DF14788D&feature=view_all