[jbob]

My girly switches the language to Japanese when she does her thing

I switch back to Australian

But again and again, it'll switch itself back again .. by itself!

Only solution is to turn off the menu bar option for language

Anybody else that uses 2 languages suffer from unwanted switching?

[Developer]

You mean switching the keyboard layout and input method.

I think this is on a per application basis so it can appear to switch if you switch applications to one your friend used before. Just press command-spacebar.

[arekkusu]

See also the "Try to match keyboard with text" option in the International>Input Menu>Options sheet.

[CharlesS]

Why don't you set up a separate user for your girlfriend? Then she can leave the language set to Japanese, you can leave yours set to Australian English, and everyone's happy.

[wataru]

Originally posted by CharlesS:
Why don't you set up a separate user for your girlfriend? Then she can leave the language set to Japanese, you can leave yours set to Australian English, and everyone's happy.

This is the answer.