vim reporting a swap file

[Bob Alexander <bob@ngi.it>]

Each time I try editing my ~/todo.txt file vim (kvim) reports the 
existance of a todo.txt.swp file which a sudo find / -name todo.txt.swp 
cannot find ...

The message also says that the file is owned by "bob" but requesting to 
delete it does not produce any visible effect.

What's up ?

TIA,
Bob