ALV output header text change

Hi, I've displayed report using ALV list, for header I've filled field catalog table using desired texts, but when I execute report, for some columns I'm getting default text for that field. e.g. For BKPF-BLDAT I've filled text as "PI Date", but when displayed it shows "Doc. Date" which is default text for BLDAT field, any solution for this issue?..............Thanks in advance