Hey, that was G-CDRB - It was sitting there having the seats reconfigured. GSM removed the front bulkheads from all the -600's and added an extra row of seats, taking them upto 131, but this particular a/c was causing real complaints as they put larger seats in and the legroom was horrific so they grounded it, it's now back to 125 seats.
Love the -600, nice dinky little a/c and very clean inside!