generated c++ doesn't compile -- please help a newbie

Hi: I'm a new user to grapheditplus (and Directshow in general). I am trying to get a simple samplegrabber program to compile. Near as I can tell, the problem is with the code that generates the pointer to the samplegrabber filter.

The graph I am using is:

Video capture ---> AVI Decompressor --> sampleGrabber --> video Renderer

The errors are:
1>c:\documents and settings\ron\desktop\capture\capture\capture.cpp(125) : error C2065: 'ISampleGrabber' : undeclared identifier
1>c:\documents and settings\ron\desktop\capture\capture\capture.cpp(125) : error C2065: 'IID_ISampleGrabber' : undeclared identifier
1>c:\documents and settings\ron\desktop\capture\capture\capture.cpp(125) : error C2514: 'ATL::CComQIPtr' : class has no constructors
1> c:\program files\microsoft visual studio 9.0\vc\atlmfc\include\atlcomcli.h(493) : see declaration of 'ATL::CComQIPtr'
1>c:\documents and settings\ron\desktop\capture\capture\capture.cpp(126) : error C2039: 'SetMediaType' : is not a member of 'ATL::_NoAddRefReleaseOnCComPtr<T>'

where lines 125 & 126 are:

CComQIPtr<ISampleGrabber, &IID_ISampleGrabber> pSampleGrabber_isg(pSampleGrabber);
hr = pSampleGrabber_isg->SetMediaType(&pSampleGrabber_pmt);

I can provide the full source code / graph file if needed.
I can get the IID_ISampleGrabber error to go away if I define the following (I don't know if this
is the correct value -- I found it googling):

static const GUID IID_ISampleGrabber =
{ 0xe784f5dc, 0xa11, 0x4c4f, { 0xbd, 0xa8, 0x15, 0xb8, 0xb, 0xe3, 0xd8, 0xc6 } }

Two questions: any idea how to fix the CComQIPtr definition so it compiles?
And How do you find the IID definitions?

Thanks

-ron