D$ = FORMAT(Date, "dd-mmm-yy") & Chr$(10)

this statement worked fine in one workbook but now does not work. "wrong
number of arguments or invalid property error is returned"
The word Format is highlighted and stays in capitals. In another workbook
Script editor accepts the "FORMAT" and it becomes "Format", and works fine.

This occured after i changed a cells date format on a particular worksheet.

Is this a bug ?