iFilter 11 doesn't work

Question

I have a small program which extracts the content of a PDF using iFilter. The code is simple and copy from this 5-star article: http://www.codeproject.com/Articles/13391/Using-IFilter-in-C

However the error I got is "Error HRESULT E_FAIL has been returned from a call to a COM component" when executing code:

Guid IFilterGUID=new Guid("89BCB740-6119-101A-BCB7-00DD010655AF");
Object obj;
classFactory.CreateInstance(null, ref IFilterGUID, out obj);

I am with latest Acrobat Reader and iFilter 11 for 64-bit machine. And my OS is Windows 7 64-bit machine.

I downloaded the sample code from that good article and got the same error.

Could anyone please help?

Answer 1

What I did just then is: removed the iFilter version 11 and then install the version 9. And how it works.

Still no idea why the new version doesn't work but old one does.