OLE DB :: 10g R2 OLE-DB Provider?

we have a client side application, on Windows and Oracle 10g R2.We use OLEDB templates from MFC (CDynamic Paramete rAccessor).There is a long query (4610 char) what provider return E_UNEXPECTED HRESULT (from execute, before the bind).

No detailed info from provider (GetErrorRecords() return E_FAIL).If I copy this query into SQL* Plus, it run without error.There is an almost the same query run successfull, the difference is only in two added order by and alias column.

recordset properties was:
stPropSet.AddProperty(DBPROP_BOOKMARKS, true);
stPropSet.AddProperty(DBPROP_CANSCROLLBACKWARDS, true);
stPropSet.AddProperty(DBPROP_CANFETCHBACKWARDS, true);
stPropSet.AddProperty(DBPROP_QUICKRESTART, true);

[code]...

connection string is:
"Provider=OraOLEDB.Oracle;User ID=user;Password=pw;Data Source=foto1;ChunkSize=4000"