Flash doesn't like MC name 'earth'?

[xTLS]

This is really stupid and unimportant but things like this bug me and make me want to know why they happen. I made a movieclip named "earth1" and put an instance on the stage named "earth". If I refer to "earth" in code I get "1046: Type was not found or was not a compile-time constant: earth." If I use any other name such as "earth12" or "earthMC" it works fine. So I already have a "solution", but what's wrong with the name earth?

[Guest]

I don't get any error messages.

Instance name : earth is OK for me.

[xTLS]

Dammit this is so weird. It's a new project, there's nothing in it but an "earth" movieclip, a "moon" movieclip, and ten lines of code. I can't imagine how it could be messed up.

edit: Well I started over and now it's fine. Not sure what was wrong last time. Whatever, probably a result of lack of sleep. Thanks.