Tramp interfering with magit

[andrea]

I don't understand why sometimes when I close some tramp connections I
get troubles with magit.  In short when I try to stage some changes and
I'm not online anymore it looks like it's trying to save some tramp
files

--8<---------------cut here---------------start------------->8---
exit

Process *tramp/ssh root@server* exited abnormally with code 255
--8<---------------cut here---------------end--------------->8---

And of course it's not able to.
Why it tries to save all the files every time I want to do some operations?
Could I set it in such a way that i doesn't care anymore of the remote buffers?