Data validation set in Excel 2010 fails in Excel 2007

I have created an Excel 2010 document that uses a drop down list in one column via the data validation feature.

The validation field is set to 'List' and defines a range on another datasheet:

=Sheet1!$A$1:$A$7开发者_如何学编程

When that document is opened in Excel 2007, those settings are lost and the drop down does not appear.

Why is that?

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The answer is that the range has to be named, and referenced like

=MyRangeName