[boost] My ports being scanned by boost.sourceforge.net?

Hi all, I've got a software firewall installed on my Windows XP machine, and while surfing www.boost.org I've received Attack detection report that said that boost.sourceforge.net(66.35.250.209) was scanning my ports (3953, 3943, 3889, 3881, 3835, 3826). What can it be? Any thoughts? -- Pavel Chikulaev