confused about backslashes

In psql:
insert into ta (a) values ('\\');
select * from ta;
returns
a
-----------
\\
(1 row)

I would expect
a
-----------
\
(1 row)

And also odbc on win is confused about this backslashes. According to
previous discussions also jdbc is confused about this. I've followed
previous discussion but nobody said that it's a bug of backend. Or or it
isn't? So then it's a bug of psql, odbc and jdbc. Could somebody say a
conclusion who should fix it?
I've seen a patch for odbc but if it's a bug of backend I think it
should be fixed in backend. Maybe it's a feature so all others should
modify their code to work well with this. But still I think that it
wasn't so in previous versions of backend and that's why all interfacing
applications expect now \ while backend returns \\. (or it doesn't ?)

I'm just a beginning user of postgresql. If you got feeling that I don't
understand a word of what I've written above, maybe you're right. I just
would like to update my linked tables in M$ACCE$ and is doesn't work.
It's not possible to change a varchar field at all. Could somebody help?