Multiple Record get - what's up?

I'm trying to batch up some record reads using an array of internal id's, it never works although it works individually for each of them.  The service login is done outside the routine and is working.  What am I doing wrong?

        private void multiGet()          {              int lotSize = 25;              int thisBlockCounter = 0;                TransactionSearchBasic CRSearch = new TransactionSearchBasic();              SearchMultiSelectField SMSF = new SearchMultiSelectField();              RecordRef[] arrRecordRefs = new RecordRef[lotSize];                foreach (KeyValuePair<string, Invoice> kvp in invoicesXML)              {                  RecordRef aRef = new RecordRef();                    aRef.internalId = kvp.Key;                  aRef.type = RecordType.invoice;                  aRef.typeSpecified = true;                  arrRecordRefs[thisBlockCounter] = aRef;                  thisBlockCounter++;                    if (thisBlockCounter == lotSize)                  {                      ReadResponse[] rr = nsService.getList(arrRecordRefs);                      if (rr[0].status.isSuccess)                          System.Diagnostics.Trace.WriteLine("success");                      else                          System.Diagnostics.Trace.WriteLine("failure");                  }                              }          }