The rpc frontpage call “put document” will not work with the new open document standard (xps) in office 2007 files. The code in the author.dll fails to find the properties when they are stored in the xps/xml format. You may want to test this using SP1 to see if it is fixed. The work around when working with xps type files such as docx is to use the “put document” and then do another rpc call “setDocsMetaDataInfo” setting the properties explicitly. The other problem with the Doc files is a property demotion issue. You may want to read the link below about document parsing with property promotion and demotion to make sure all things are aligned for this to work.
After uploading a file you can examine the metadata that is generated for the document in the “AllDocs” table in the corresponding content database in sql server. Below is an example of what is generated in the metaInfo column of the table when you upload a file.
vti_error0:SX|Could not process the file mosstestsearch/test.doc as a Microsoft Office document.
vti_cachedcustomprops:VX|Subject Keywords _Author _Category _Comments
You can see when uploading Office 2003 files SharePoint adds a metadata error entry “vti_error0″ stating “Could not process the file as a Microsoft Office document”. Hmmm. I do believe this is an office document, just not an Office 2007 document. The document’s properties are promoted correctly because I can go into the SharePoint UI and view the properties. For instance, vti_title maps to the title property and testcol maps to the testcol property. Unfortunately, if I open this document in Office 2007 none of the properties are visible. So why are these properties not getting demoted correctly? The key here seems to lie with the “vti_cachedcustomprops” property.