I cn only speak from a Windows Standpoint, but Maya uses the Machines Clipboard for anything like text, filenames etc...
To get Geometry to paste into a scene it would have to have been copied or cut and then pasted into the scene. Normaly you would duplicate or import geometry into a scene. So I have no idea what you did to get the geometry in, maybe it was still in the clipboard.
Chris (formerly R@nSiD)
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