You got a 1933@1953 You bought yours in the future ?
I think you have a 1633@1653, just like I have... I couldn't get any decent burns with my 1633s with stick firmware, So I got the firmware of the CodeKing (CS0M) and did a reset of my eeprom... after that I finally got GOOD burns @8x, BUT I must tell you that I only get good burns with GOOD MEDIA!!!
What media do you use? I advise you to buy some Fuji's with Tayo Yuden Media code... I got really good burns with them and you can buy them cheap @ www.cdrwinkel.com or www.cdrwinkel.nl