The reply to just stopped working.
What version of Windows and eM Client are you using?
What happens when you click on either of the reply buttons? Are you getting any errors?
Did you restart the application, and try again?
V7.1.31849.0 I am not an idiot. Yes I restarted the application again and again. Duh! There are no errors. If I select the reply button absolutely nothing happens.
Can you upgrade to the latest version at http://www.emclient.com/release-history and see if there is any difference?
Also, check that your .NET Framework is updated.