TableView bug?

[Robert Fisher]

Hi guys,
 
I am having some difficulties fine-tuning the style of my TableView and I'm wondering if I've found a bug.
 
It may well be related to an existing JIRA issue, so I thought I'd check here first to see if I should create a new one.
 
http://i.imgur.com/9tGc2FB.png
 
These screenshots are taken from the latest Ensemble app. Look carefully at the separator between the two column headers. Initially, and after resizing a column, you see the top version. The header width is 1 pixel too short, and the border is therefore drawn 1 pixel too far to the left.
 
After clicking on the header to change the sorting of rows, you see the bottom version. This looks better.
 
Is this a known bug?
 
Cheers,
Rob