Aero Commander

I have been using the Aero Commander from Aero Design Engineering. The aircraft is very unresponsive to pushing the stick forward. There is some descent but not very much. Looking at an outside view there does not seem to be enough movement in the control surfaces. Any suggestions?
Warren.

Thank you Yoland for your very kind reply.
Let me try your suggestion regarding the autopilot as this sounds a very possible solution.
Also I will wait to see whether you can find an upgrade to the air file or config file.
Tuesday and Wednesday are not suitable at the moment for Skype.
Let's try the other things first and I will let you know what happens.
Warren.

Yoland you were dead right about the autopilot. I restarted my last flight using Autosaver and had no problem when I set both the altitude and rate of climb back to zero before beginning my descent.
Many, many thanks.
Warren.

Thanks Ricardo,