Invisible insertion point in field

[David Wilkinson]

I imagine there is an obvious answer to this but I cannot figure it 
out.

I have uploaded an experimental table field stack to my user space 
(user227), which uses work by and ideas from Chipp Walters, Sarah 
Reichelt and Scott Rossi.  It has an edit field that sits on top 
of a  worksheet/grid field. The problem is that although you can 
enter text in the edit field, the insertion point is invisible. Does 
anyone know why this might be?  One possible clue is that in order to 
drag the field with the left mouse button, the field has to be locked 
when the mouse enters its border zone and the insertion point does 
not show in lockedtext fields - but then you can't enter text in such 
field either.

As a side question, is there any reason why Rev should set the 
vscroll of this field to 4?  I cannot recall any code that scrolls it 
directly and notionally the textheight and textsize are the same as 
the underlying field.  I suspect this might be tied to the vertical 
offset from which text entered into fields, with hgrid enabled, seems 
to suffer.

TIA

David Wilkinson