[Contributed by a 567 student:]
On Linux, the LKB dialogs that take textual input (e.g., the one reached from View/Type definition...) treat CUA keybindings like Ctrl-X and Ctrl-V as just another character. Instead, to paste into them, use Shift-Insert. To cut, use Shift-Delete. I don't know a shortcut for select-all other than Home followed by Shift-End.
-- Main.ebender - 2012-01-18