Thanks!
Now I'm having another little problem. I made a little squashed-globe shape and used the perspectives tool to rotate it, and no matter what image format I save it in, I can't paste it into my bedroom so that I can see whether the perspective is correct. Every time I copy it, then go to the bedroom file and select Edit/Paste, something else that I copied a few hours ago gets pasted in.
Has this sort of thing ever happened to you?
Never mind... Solved the problem by deleting the image that kept getting pasted in when I tried to paste in something else.