One enforced change (Yakubu for Hasselbaink) cannot be to blame as the team struggled to gel and failed live up to last weeks perfomance.
Had Yakubu scored with just five minutes gone it could have been a different story, but Charlton dominated, with Dennis Rommedahl and Jerome Thomas giving the Boro defence a torrid time.
Two second half substitutions were strange to say the least, the lively James Morrison being replaced by Gaizka Mendieta and Franck Queudrue being replaced by Emanuel Pogatetz.
Ok, Boro needed to compete in midfield, but for me Stuart Downing was out of sorts and Michael Reiziger is not a Premier League player.
An injury to Mendieta after just ten minutes meant the introduction of Massimo Maccarone, which lifted the Boro crowd for a while, but two late goals by Charlton sealed Boro's fate.