It's probably something fairly simple. Why don't you post a copy of your file so we can take a look.
I have now done something else silly and the layout is only showing a single record. I would send the file, but I am not sure how to on this forum. I think you are right, I feel it is simple, but I am such a novice at this, I can't see how.
To attach your file click on "use advanced editor" in top right corner of this panel. You may get a dialog asking whether you want to leave the page you are on—allow this. The advanced editor then has a "chooe file" button at the bottom which you can use to select and then upload your file.