Ok here wo go.
DirectX 9c is not Direct9c. It depends on the runtime build
. For normal Users don't understandable, but it is like it is.
It's an common Microsoft SLA that you always have to install the newest DirectX runtime!
Every commercial Game brings a DirectX runtime with it and installs it during Game installation.
We don't include directx into our Installer, just because the runtime is to big. We mentioned it everywhere on our Site (mainpage, downloadpage, install manual), that you have to update your directX.
So i see no need to include it.
Now to the problem. Ogre 1.4.7-current (1.4.9) is compiled against the August 2006 SDK of Directx.
So it's no Iris issue, it's an Ogre issue.
Now why is not build against the very old DirectX SDK from 2002? Just because the runtime was updated for bugfixes and Speed improvements.
Also if you play other commercial Games, you should have a newer runtime then August 2006. So you shouldn't have this problem.