Thanks to a heads up from Kitetsu07 in this thread in the AutoCAD® Architecture Discussion Group, I can pass on this CUI adjustment to get Paste to Original Coordinates and Paste as Block on the right-click context menu to work in the 2010 release. There is a stray "&" character in the Display Name of these context menu options that results in them being grayed out.
Open up the Customize User Interface dialog (type CUI at the Command prompt, or find it on the Ribbon on the Manage tab, Customization panel), and in the upper left area, under the ACA customization file node, expand Shortcut Menus > Context menu for edit mode > Clipboard. Select the Paste to Original Coordinates item and, in the Properties area (lower right area), delete the "&" in front of "Original" in the Name property under the Display node.
Do the same for the Paste as Block Ctrl+Shift+V item, removing the "&" from between the "B" and "l" of "Block" in the Name property under the Display node.You do, of course, have to have content on the Clipboard that AutoCAD Architecture can paste into a drawing for the Paste as Block option to be active and you need to be in a drawing other than the source file of the objects copied for the Paste to Original Coordinates option to be active. If you would prefer to avoid editing the CUI, you can still type the commands (PASTEORIG or PASTEBLOCK) or use the Ribbon, Home > Modify > Paste flyout on Modify flyout, as shown below.I would rather take the time to fix the CUI, than waste way more than that surfing the Ribbon for these paste options.