Unable to insert Date Created attribute

[teratorn]

There is some problem that prevents me from being able to insert the Date Created attribute on an item.

I right-click in the empty white space of the Item Attributes pane, and click Insert, then I type in "Date Created" for the attribute name ("Date Created" is not available in the drop-down list, why not?)

Then I give it a Category of System and a Type of Date+Time, when I click insert an error MessageBox appears: "Error inserting attribute: Attribute names must be unique (case-insensative comparison)"

I can, however, create a new attribute with the name "Date Created" (NOTE the two spaces between "Date" and "Created"... this works because it doesn't conflict with the name "Date Created" which is a built-in System attribute, but why doesn't it show up in my list of attributes?

Also, when I use the Advanced Search interface it doesn't show up in that list of attributes either.