The URLs differ in mode=replies variable, which is the default mode. This is a general problem with Joomla components - they sometimes display different URLs for the same page, just one URL omits variables with default values.
We'll handle this one in next version of our Kunena extension.

Hi,
Thank you for the information, we'll integrate the option in next version of Kunena extension.

Hi,
It's still on our TODO list, we just haven't got to it yet.