I use xampp under Ubuntu 11, I delete the xampp once(everything works fine before this deletion),  after I unzipped the xampp again and put drupal-7.4 under the htdocs directory. 
 
some strange error happened:
 
--------------------------------------------------------------------------------------------------------------------------------
warning you are not using an encrypted connection, so your password will be sent in plain text, ----
--------------------------------------------------------------------------------------------------------------------------------
 
when I use the administrator account this time:
 
----------------------------------------------------------------------------------------------------------------
Failed to connect to server. The server reports the following message:---------------------
Cannot connect to FTP  Server check settings.                                        --------------------
----------------------------------------------------------------------------------------------------------------
 
any thoughts..... thanks..
 
 
this drupal setting almost kill me ....