Whenever you copy a cell or a range of cells in Excel (my version is 2010 on Windows 7), and then do something else like insert new sheet row or simply edit another cell, Excel removes the clipboard data. For me this seems to me so utterly stupid and it's very frustrating (probably it has some logic behind it like preserving references or something like that, but I don't think it would be rocket science to make it work like any other program that has Copy-Paste available).
The only workaround is to use the Office clipboard, but I don't want to (uses space on the screen and it's a lot less comfortable than CTRL+V) and I don't think I should be forced to use it.
Here's a reference to some posts also complaining about this problem:
Is there any way I can force Excel to keep my data into the clipboard until I decide I don't need it no more instead of it, without using the annoying (to me) Office clipboard? Maybe using the Windows clipboard.
Or at least you could explain to me why this is happening (I know this is normal behavior, but why?)