Problems getting DVD to work

I have 2 Sony DVD RW AW G170A SCsi Dual Layer DVD’s in my computer. I had problems getting them to work properly. I took one out and after a lot of research found I needed to edit the registry to get the record tab to appear. It was set to 3 in the registry, and by changing it to 2 worked a treat. So I thought I’d put my other Sony back, prob is this don’t wanna work. Ive changed the number in the registry and also made sure I have the latest drivers but to no avail. The second DVD appears in device manager. I can view properties for this device, although it takes ages to appear. I suspect some sort of conflict, but seem to be stuck. I’m using XP by the way and have disabled any virtual drives and uninstalled Nero 6. Any help would be much appreciated.