[checklink] very long checking times - any idea?

Hi,

I just got reports of "sluggishness" for checklink. I checked, and it 
seems indeed like checklink takes > 5 seconds to HEAD each resource.

sample below
[[
HEAD http://www2003.org/  fetched in 5.3s
Checking link http://www.w3.org/Icons/WWW/w3c_home
HEAD http://www.w3.org/Icons/WWW/w3c_home  fetched in 5.0s
Checking link http://www.w3.org/QA/Activity
HEAD http://www.w3.org/QA/Activity  fetched in 5.0s
]]

The server is, however, not awfully overloaded, and although it has 
suffered a DOS attack recently, I doubt this is related.

Ville, do you have any idea what could cause this, or any experience of 
similar trouble?

-- 
olivier