bytea question

PG 8.4.0 running on Mac OS 10.6.1

Could anyone tell me why the bytea datatypes seems to like some bytes better
than others?

testdb=# create table byteatest(blob bytea);
CREATE TABLE
testdb=# insert into byteatest (blob) values (E'\\007');
INSERT 0 1
testdb=# insert into byteatest (blob) values (E'\\008');
ERROR: invalid input syntax for type bytea
LINE 1: insert into byteatest (blob) values (E'\\008');

Or also:

testdb=# SELECT E'\\001'::bytea;
bytea
-------
\001
(1 row)

testdb=# SELECT E'\\008'::bytea;
ERROR: invalid input syntax for type bytea
LINE 1: SELECT E'\\008'::bytea;

As far as I can see i followed the escaping rules given in

http://www.postgresql.org/docs/current/static/datatype-binary.html

Thanks,

Maximilian Tyrtania