> cannot copy <http://plantes.sauvages.free.fr/>

You won't, because online/free.fr is filtering various 
offline browsers, mainly due to bandwidth abusers.

To download this site: first setup reasonnable bandwidth 
settings:
- 'Set options'/'Flow control'/'Number of connections' :  
no more than 2 or 3
- 'Set options'/'Flow control'/'Limits'/'Max transfer 
rate': no more than 10000 B/s

then:
- 'Set options'/'Browser ID'/'Browser identity' : set the 
ID to Netscape or IE one depending on the final browser 
used to see the site (some sites has different content, 
depending on the agent)