> ë --> ë
> This looks like UTF-8 charset, but displayed as Latin-1.
> My guess: 
> the webserver sends a Content-Type: text/html; 
charset=UTF-
> 8 HTTP header.
> The page is saved litterally by HTTrack, but HTTrack does 
> not transform the HTTP header into an equivalent META 
tag, 

This is done in the current 3.30-RC :

3.30-RC
..
+ New: HTTP-headers charset is now propagated in the html 
file

Can you try with the 3.30-RC4 please?