What (as has happened before) SMWS can lose track of numbering if there is a large time gap and not realise a number has already been used.
Thus you have:
11:26 bottled Jan 2003 (European/Japan 70cl release)
11:27 bottled 2003 for US Market only (750ml)
Then for the next European release in 2006 they continued numbering from the last one they had records for, hence this:
11.27 bottled Sep 2006 (70cl)
Curiously the strength of both the 1978 750ml US 11.27 and this 1990 70cl release is 54.6, but this looks to be one of those coincidences.