This afternoon, having nothing better to do

, I decided to convert a 281 pub to 04. This pub is actually a combined phrase book and thesaurus and consists of several hundred pages. From this you can deduce that there are a lot of words in this pub.
In 281 I had the Spelling Language set to British English. I checked that every word was spelt in accordance with standard British/Australian usage. A spell check identified no errors, and no errors were marked when I used the editor.
In Opus 04 I have the Spelling Language set to British English. After opening the pub in 04 and adjusting fonts and paragraph settings, I decided to check the tect.
Despite my having set the Spelling Language to British English, Opus has reverted to standard American English usage, and marks all the correctly spelled British English words as errors.
I know I can correct this by adding the hundred or so variants to the custom dictionary, but this should not be necessary.
Is there any chance that Opus 04 was provided without a British English dictionary? or could it be "locked" to use American English despite the settings in Tools > Options > Spelling?