All the comics and images that were removed have already been scanated just FYI.
Strips that have been removed
"For some reason they sleep naked"
"Germany and the drug store"
"England's plan to be the strongest"
"Japan has a cold"
and a pic from "Comic Diary 4" labeled "charasyo.jpg"
What is weird about this is that a couple of these strips has been adapted into an anime segment.
This isn't the first time Himaruya has deleted stuff from the site. A few Hetalia comics have been removed in the past and material from several other webcomics as well (most notably the majority of Advance! Kitakou Broadcasting Club Pure).
UPDATE: It appears the images have been put back up. Odd. Maybe it has something to do with that organization chasing Himaruya? >.>
Though the answer may be simpiler than that - The original location for "For some reason they sleep naked" is - http://www.geocities.co.jp/himaruya/nazene.htm and now its located here - http://www.geocities.jp/himaruya/nazene.htm
The only image that appears to still be gone is "charasyo.jpg" from "Comic Diary 4"
Sorry for the scare!