incrediBILL - 8:08 pm on Mar 2, 2012 (gmt 0)
After having evaluated some data from a site being hit by this bot attack I believe that I can now effectively block this traffic.
Unfortunately, this is a website analytics forum and not the Apache or Spider ID forum, so I certainly can't provide any specifics here as it would be off topic and off charter ;)
However, I will say that traditional log files, as usual, were completely useless in figuring out a solution to the problem. When it comes to logging and analysis of bot traffic that looks like MSIE, if you aren't tracking all header details, you're just wasting time.