Problem with field borderwidth 2

[Wilhelm Sanke]

A stack developed with Metacard 2.5 contains several rows of adjacent 
fields - with the default borderwidth of 2 when the stack was created. 
The adjacent fields are placed relative to each other in such a way that 
the borders form smooth vertical and horizontal lines between the 
fields, giving the impression of a "net" in which the fields are 
embedded. The fields are on top of an image (which is intended to become 
visible when the fields are removed one by one when working with the stack).
The horizontal and vertical "lines" show as intended until engine 
version 2.5.1B3 (Metacard reading).

 From engine version 2.6.1 on - corresponding to Rev 2.5 and later - 
suddenly the underlying image shines through between the fields although 
they have not been moved.
Setting the borderwidths of the fields to 1 or 3 restores the "lines" 
between the fields - now of course of different width - and the image is 
no longer visible.
Setting the field borders back to the default width of 2 lets the image 
shine through the fields again.

This is on WindowsXP and holds both for the Rev and Metacard IDEs, 
meaning it is an engine problem.

Has anybody else noticed this or can verify my observation?

--Wilhelm Sanke
<www.sanke.org/MetaMedia>