I'm using this code to search documents using FullTextSqlQuery:

strQueryText = "SELECT ID, workid, write, size,TitleDoc FROM SCOPE() WHERE \"scope\"='centredoc' AND isdocument=1 AND FileExtension<>'ASPX' AND StatusDoc<>2"

FullTextSqlQuery FRequest = new FullTextSqlQuery(ServerContext.Current);

            FRequest.QueryText = strQueryText;
            FRequest.ResultTypes |= ResultType.RelevantResults;
            ResultTableCollection resultTbls = FRequest.Execute();

- ID, workid, write and size : antive fields

- TitleDoc: a property mapped to a custom field[ this custom field inhirt from SPFieldText.

When i execute this code:

 -For doc and ppt documents i get all métadatas.

- For pdf documents only TitleDoc is always empty. Did this problem occur for u? can u help me to fix it?

thank u