Strange error log. Is this a hacker?

[dschwab9]

I just looked at my error log, and I've been getting errors like the one below for 12 hours solid, all from the same IP address, but with different session numbers.  Is this a hacker?  Should I be concerned about it?

Guest : 66.77.73.140 : Today at 09:46:03am

/yabbse/index.php?board=2;action=post;threadid=14;quote=89;title=Post%2Breply;start=0;sesc=0b1f93c171df07baa6b8933f8d19cfe7

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Guest : 66.77.73.140 : Today at 09:48:14am

[Peter Duggan]

It looks like a crawler:

http://ws.arin.net/cgi-bin/whois.pl?queryinput=66.77.73.140

http://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=%22fast+search+inc%22

[Ben_S]

Server:  resolver1.th.eclipse.net.uk
Address:  212.104.130.9

Name:    cr001r01.sac2.fastsearch.net
Address:  66.77.73.140

Looks like a search engine trying to spider your site

[dschwab9]

Thanks.  It scared me, so I didn't even think about looking up the IP  

I feel better now tho  

[Daniel Hofverberg]

In case you're wondering, Fastsearch equals www.AllTheWeb.com