The 8x DVD writer on my Dell laptop suddenly writes very slowly--a 4GB DVD takes about 1.5 hrs, running at speeds up to only 0.8x. Have tried two different softwares (Roxio and Nero) and two different discs (Sony and Moserbaer) and all have the same problem. Also, when the DVD write gets up to about 150 MB, the writing slows down and almost stops--after multiple attempts a single MB is written, and then writing continues normally at the slow 0.8x speed. Have tried to clean the laser head in the DVD drive, but nothing seems to make much difference. Do I need to replace the drive--it still works, but only at 1/10th speed?