I don't know exactly when this changed, but I once was able to use <shift><alt> to block-select text (i.e. with arrow keys or mouse clicks) then immediately use <Ctrl><C> to copy the text or <delete> to delete it. Currently [version 7.13 HF3 (188.8.131.5238) (32-bit, PC)] the focus, after block-selecting, moves to the tool bar above the editor disabling any keyboard shortcut on the text that was recently selected.
One present solution whereby the user right-clicks on the selection to choose an action on the drop down menu, is present, but its not as good as it was when the shortcut keys could be used. (please, thanks)