Thank you Dan.
Due to the tendency for me to not always get the Windows Clipboard when pasting in ME, I changed the keymapping so that Ctrl+V ran "Paste Special" rather than Paste. So, I was ONLY using the Windows Clipboard not realizing that additional block information was stored in the ME paste buffers which gave me the functionality I have come to depend upon!
I will go back to using "Paste" and reconsider when to use "Paste Special".
Thank you again for your response which pointed out my idiocy.