spell check and deictionary not working

When i start the application up and i try to type some thing it says, Could not load the dictionary for english (australia)[en-AU]. I went to tools\set language and changed the the defualt from australian, thats where im from but i figured that its not compatable with australia dictionary. So i changed it to US. Spell check doesnt work and it goes back to australian english if i close the program. I havnt been able to get spell check work once. Help me please.