Komento - Reply button not showing in comments in article integration

In an earlier version of Komento (I think 1.6.3680) the reply button was available (if configured) to allow reply to comments. Now using version 1.6.3808 (following uninstallation and re-installation) the button is no longer visible so no replies can be entered.

Comments can be added normally (by registered users only).

We have checked the configuration but can't see a problem. Using Joomla 2.5.9 (No change) and no further extensions loaded.

Any ideas on what we should be looking for? Many thanks.