round-triping bytea/buffers

The following script fails with a segfault:

----
import psycopg2

conn = psycopg2.connect(DSN)
cur = conn.cursor()

cur.execute("create temp table foo (id integer, data bytea)")

data = '\x00\x01\x02'

cur.execute("insert into foo (id, data) values (%s,%s)", (1, data))
cur.execute("select data from foo where id=1")
data_fromsql = cur.fetchone()[0]

print "data from sql", repr(data_fromsql), repr(str(data_fromsql))

cur.execute("insert into foo (id, data) values (%s,%s)", (1, data_fromsql))
----

Like so:

2.0.6 (dec dt ext pq3)
data from sql <read-only buffer for 0x2aaaaab12270, size 0, offset 0 at
0x2aaaae7bf1f0> ''
Segmentation fault

However, if I instead do this this:

data_fromsql = cur.fetchone()[0]
data_fromsql = buffer(str(data_fromsql))

...the script works. It seems the buffer objects that psycopg returns
cannot be passed back to psycopg.

Version as above is 2.0.6