First one,relating to mldonkey,it seems that i didn't uninstall mldonkey-server completely.
And these still existing files ensure me:
I used "sudo aptitude remove --purge mldonkey-server" to uninstall it.
So just removing the two files mentioned above will solove this problem?
it is about Networkmanager.And i have no idea about the reason of this.
According to Google,it seems a bug that haven't yet been fixed.
My OS:Ubuntu 8.04
Here comes the screen: