Why Spell Check and History Don't Mix

Updating Open Office has left me with a dictionary which recognises only words I've added to the dictionary since installing Open Office in 2009. The results are fairly hilarious...

Aethelred
Alcuin
Anglian
Athelstan
Cuthbert
Faroe
Finchley
Frisia
Guildsmen
Hanoverians
Hemel
Hempstead
Justinian
Lindisfarne
Mercia
Merovingian
Offa
Picts
Plantagenet
Pompei
Prussia
Regnal
Toponym
Vinland

A broadly accurate summary really...