PL/R Median Busts Commit (Postgres 9.1.6 + plr 8.3.0.13 on Ubuntu 12.10 64 bit)

I admit - it sounds unlikely. However a simple scenario (attached) gives
rise to:

WARNING: AbortTransaction while in COMMIT state
PANIC: cannot abort transaction 880983, it was already committed

Essentially we are doing:

BEGIN;
DROP TABLE IF EXISTS tab0;
CREATE TEMP TABLE tab0 ( id INTEGER PRIMARY KEY, val TEXT);
INSERT INTO tab0 SELECT generate_series(1,1000),'xxxxxxxxxx';
SELECT median(id) FROM tab0;
DROP TABLE IF EXISTS tab1;
CREATE TEMP TABLE tab1 ( id INTEGER PRIMARY KEY, val TEXT);
INSERT INTO tab1 SELECT generate_series(1,1000),'xxxxxxxxxx';
DROP TABLE IF EXISTS tab2;
...
DROP TABLE IF EXISTS tab99;
CREATE TEMP TABLE tab99 ( id INTEGER PRIMARY KEY, val TEXT);
INSERT INTO tab99 SELECT generate_series(1,1000),'xxxxxxxxxx';
SELECT median(id) FROM tab99;
COMMIT;

We crash at commit.

Changing median to something else (e.g avg or even a non PLR median
function) makes the error vanish, so its either PLR or the specific PLR
median function causing the grief.

Regards

Mark