Hi Mike,
This is a documentation problem. TextAlign_XXX flags are not applicable to TreeBoxNode columns. Use the following constants for calls to TreeBoxNode.setAlignment() :
#define Align_Left 1
#define Align_Right 2
#define Align_Center 3
Note that vertical alignment cannot be set for TreeBoxNode objects. Note also that you have to call setAlignment() for each TreeBoxNode that you create, that is, alignment (as the rest of node visualization properties such as font, color, etc) is a column property of each individual node, not of a table column.
In the next version I'll include a pjsr/Align.jsh header with these constants.