Could simply be a compatibility issue and may require ACR 7/7.1. Check the list: Camera Raw plug-in | Supported cameras. For more help ask on the ACR/ PS forums. chancers are better someone there might actually know what to do...
I have tried this and did so again following your link.
I download CameraRaw 7.1
Opened the Adobe Patch installer.
A dialogue box comes up recommending I extract all files first. (the Extract All Files First check box is highlighted.)
I do this. I now have Adobe Patch installer with the red Adobe symbol.
I click on this and up comes – Adobe Application Manager. “Update Failed”
Suggests I go to Customer Support. ????
Back to square one!
It must be something simple, something I’m just not getting.
More help please!
First thing first , You have PS CS5.1 so you cannot install the Camera Raw 7.1 update . Photoshop CS5.1 only support camera raw 6 to 6.7 , the 7 series of camera raw is for the Photoshop CS6.
Now , you concern , if you have the Photoshop CS5.1 then you have to make sure you have updated your Camera Raw plugin to 6.6 atleat.
Check this link for the added Camera with the Camera Update 6.6 and to download and install the update.