Is this a bug?

 From:  BurrMan
2399.2 In reply to 2399.1 
Hi David,
Your file works ok if you extend each object a bit through each other. These kinds of operations where things just "Graze" along an exact edge can give problems to the intersection mechanism.

How did I do? Do I sound like Michael at all?? :)

EDITED: 19 Jun 2012 by BURRMAN