Paul,
I've never worked with the Range collection of a Range before, so I don't know how looping through that collection works. Do you have any other ranges that intersect with column A of sheet Database? If so, try declaring rngData as a Variant and adding .Cells to the end of your For Each ... statement so that you loop through the cells in a specified range, rather than through the ranges.
Hope this helps.
Regards,
Batman.