Drop Down Lists 2007

I have followed all the steps in creating a drop down list in Excel 2007:

Created Named list on seperate sheet
goto the sheet that the drop down will be on and select the appropriate cell
Data Data Validation Allow:List Source: =BlahList Click "OK"

....And then, I get this message every time:

"The list source must be a delimited list, or a reference to single row or
column."

So. What am I doing wrong? Ive been to Youtube, and read numerous articles
on here about "Drop Down Lists" and still am having an issue with this one
feature. Thank you for your time and attention in this...