Hi Naoto,

This feels like the sort of temporary error state sometimes seen with asynchronous or shared connections... except that SQLConnect is not shared, ASYNCHRONOUS false and BATCHMODE true. So SQLEXEC should never return 0 (still executing)... but if it did, this code will call that an error. Perhaps isolate SQLEXEC's 0 return separately, in case that's somehow the cause:

    nRet = SQLEXEC(m.hConn,"SELECT * FROM dbo.SYSCONF","RV_Sysconf")
if m.nRet=0
    Error "Database asynchronous SQLEXEC should not have occurred"
Else
    IF nRet < 0 THEN
      local laError(1)
       aerror(laError)
       Error Transform(laError(1,1))+": "+laError(1,2)+NVL(": "+laError(1,3),"")
    ELSE
        *
        * some other stuff happens here.
        *
        USE IN (SELECT("RV_SysConf"))
    ENDIF
endif

Also I'd recommend using AERROR() to try to refine any ODBC error return... elements 4, 5 and 6 could give you an "aha" moment.