Pfui - 5:59 pm on Nov 11, 2010 (gmt 0)
Still hitting bare (no rDNS), but at least asked for robots.txt this time:
Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)
Hmm. Bare MSN IPs get the standard disallow version of robots.txt, the official .search.msn.com/msnbot/bingbot bots don't. Yet another IP/UA variation/combination to code for? MSN, Google 's new Web Preview UA [webmasterworld.com...] -- it's never-ending, I tellya.