How do you programmatically update the metadata "summary" and "description" items?

[WilliamKirchhoff]

Is there a way to programmatically update the Summary / Description / Credits and Use Limitations items that appear at the beginning of a metadata description in ArcCatalog?  I use IMetadata  & IXMLPropertyset to update many of the other elements of a metadata record for a featureclass I have created, but I am unable to figure out how to get at these items.  I have searched through the XML output from the ArcCatalog metadata Export function, but I can not find elements relating to these items.

[NeilClemmons]

I'm not sure exactly which metadata elements you are referring to but a good way to find them is to use the metadata editor dialog to set the values to something unique and then switch the stylesheet to xml and find the values.

[WilliamKirchhoff]

Neil,

Thanks for the reply, your suggestion is the logical one I have been trying for some time without success.  Unfortunately, heres what happens when I use this approach:
1. I open a newly created featureclass ( arcgis desktop 10 SP3) using the Catalog Item Description context menu choice in ArcMap.
2. The Item Description dialog pops up and I select the description tab and click "Edit"
3. In the ensuing editor I enter text into the Description, Summary, and Credits fields.
4. I save my changes then select "Export" back in the Item description display window.
5. Once the export has successfully completed I open the resulting xml file in XML editor and look for my entries.
Shazam!  There they are:
The string I entered into the Summary field in the editor shows up under:
   "identificationInfo/MD_dataIdentification/<purpose>
The description string appears under:
   "identificationInfo/MD_dataIdentification/<abstract><gco:characterString>description_String </gco:CharacterString>
and the string I entered under Credits appears under :
   "identificationInfo/MD_dataIdentification/<credit> element.
BUT...
In my code I try to load my new featureclass specific data for these elements using the following example for the description field:
pXMLPropertyset.SetpropertyX("identificationInfo/MD_DataIdentification/abstract", <description_string>,esriXMLPropertyType.esriXPTText,esrimlSetPrpertyAction.esriAddOrReplace, False")
which runs, but the <description_string> does not appear in the esri Data Identification display window instead there is this entry:
identificationInfo/MD_dataIdentification/<abstract gco:nilReason="Missing"/>

Given that my understanding level of the metadata system esri now has in place is minimal, I could be making a very simple mistake and wouldn't know it.  Any further thoughts?