Pioneer 105 DVD Writer Problems

Hi

I have had problems writing with my new DVD Writer. It is a Pioneer 105 and I hasve managed to burn CDR’s with no problems using Nero, CDR Clone & Music Match Jukebox. I am however having problems copying DVD’s. In fact I have not managed to copy one yet. I have tried using Nero & Prassi Primo DVD2. Nero comes up with a error message saying “Burn Failed Power Calibration Problems”. I have tried copying at all speed 1,2 & 4 speed. I have tried on the fly and from an image file. I am using Datawrite DVD-Rs with nothing stated on it as to what speed it burns at. It has a purple recording surface. My PC is a Athlon 1600XP with 512MBDDR Ram, 60GB Harddrive, Windows XP. I have set the DVD Writer as the Primary Master, Harddrive as the Primary slave and the DVD Rom Drive as the Secondary slave. I have connected the harddrive and the DVD writer on the same cable and the DVD Rom on a seperate one. Where am I going wrong??? I see there is a 1.21 firmware update for the drive do I need to install this or like some of the cautions say am I likely to damage the DVD Writer by doing this. I am sorry but I cannot tell you what firmware version it is at present as I am working away from home but I could get back to you with this if it is required. Please please help me out befor I trash another £25 worth of media. Thanks for you help.

Cheers
Scott