MSNPTC/1.0 appears to be a poorly written spider bot. It has no concept of distributing requests. I am not the only person that thinks this:

http://www.webmasterworld.com/forum11/2845.htm
http://www.botsvsbrowsers.com/details/4800/index.html
http://boardreader.com/t/Spiders_Crawlers_509179/MSNPTC_1_0_2849.html

Let me demonstrate with an example:

$ grep -c “MSNPTC/1.0″ freshports.org-access.log
1975

$ grep “MSNPTC/1.0″ freshports.org-access.log | head -1
219.142.53.25 - - [01/Nov/2007:16:52:00 -0400] “GET /login.php?origin=%2Fcommit.php%3Fcategory%3Dwww
%26port%3Deventum%26files%3Dyes%26message_id
%3D200708050837.l758baWl059884%40repoman.freebsd.org
HTTP/1.1″ 200 16533 “-” “MSNPTC/1.0″

$ grep “MSNPTC/1.0″ […]

Some of you will have noticed that we had a short outage on the FreshPorts webserver yesterday. It would have appeared as if the webserver was not responding. It was being slow. Very slow.
The cause is interesting. When I checked the logs, it was my ad server that was busy. […]

Just in case you use Cacti: Cacti remote injection exploit