After much investigation by myself and Logitech, the keyboard manufacturer, it has been established that it is not a USB issue after all. The keyboard is starting up after Sleep or Hibernate, but the Macro function is not enabled.
The Logitech technician tried various cures, but we couldn't resolve it, so it remains a software mismatch with Vista.
A work-around was found, however. I right click on the Keyboard icon in the system tray, and select Exit. This stops the program. Then I go to Programs and start it again. I have pinned the program to the Start menu for ease of access.
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