motorhaven - 3:54 am on Nov 15, 2011 (gmt 0)
Everything I've gotten (thousand of hits, its a forum with a very high page count) shows the 65.52 is legit for the crawlers.
Out of thousands of hits from the 65.62.#*$!.#*$! range the vast majority identify as a Microsoft crawler. These all fetch robots.txt and obey it.
The IPs below come in looking like either a user, or a stealth checker, but are rare in nature, hit a few pages and then leave. No search engine UA with these.
These do not fetch robots.txt but do obey it.