Well, this string uses the "plural" setting :
Filestats for this session: Accepted %d of %d request, %s transferred\n
and shows up as only one entry in poEdit but with the plural tabs to allow entering what is required when there is more than 0 or 1 request.
On the other hand, this string does not use the "plural" setting :
Are you sure that you wish to delete the selected friend?
It shows up twice in the file, one for 0 or 1 friend, another one for when there are many friends to delete.
I don't know how these strings are extracted but it might well be that some are not extracted properly.