Error message when using XlCoerce with Excel 97: "Unhandled Exception in Mso97.dll"

        /*********
      *  RangeContainsText
      *
      *  Purpose: Determine if a XLOPER reference points to a range that
      *           contains any cells containing text.  Microsoft Excel 97
      *           stops responding if XlCoerce is used to convert a
      *           reference to a string.
      *
      *  Parameter:
      *           pxRange[in]    Range to check.
      *
      *  Return:  TRUE  -  Range contains text, or Excel4 call fails.
      *           FALSE -  Range does not contain text and it is safe to
      *                    use XlCoerce on the reference as a workaround
      *                    to the problem.
      *
      *******************************************************************/ 
      BOOL RangeContainsText(LPXLOPER pxRange)
      {
         DWORD dwRet = 0;
         XLOPER xIsText;
         BOOL bRet = TRUE;  // Value returned if Excel4 Fails

         // Check determine whether you are working with a range
         if( !((xltypeSRef | xltypeRef) & (pxRange->xltype)))
            return bRet;

         dwRet = Excel4(xlfIstext,&xIsText,1,pxRange);
         if( xlretSuccess == dwRet && xltypeErr != xIsText.xltype)
         {
            XLOPER xRet;
            dwRet = Excel4(xlfOr,&xRet,1,&xIsText);
            if( xlretSuccess == dwRet && xltypeBool == xRet.xltype)
               bRet = xRet.val.bool;
         }
         Excel4(xlFree,0,1,&xIsText);
         return bRet;
      }