Laptop DVD drive shot?

I've had my laptop (Acer Aspire 5630) for about a year now and just recently my DVD+R DL RW has stopped burning DVDs.

Reading and writing CDs works as I just played an audio CD and I tried burning pictures as a data CD, reading DVDs also works, but when I try burning DVDs - I've tried burning a movie using Nero Vision (which I've done hundreds of times before with the same software and drive), and just a regular data DVD with .exe's and .avi's, I always get the same error using Nero "Power Calibration Error". What happens is the progress bar will go to 1% and the drive will get louder, and sort of 'stutter' and then give me the error message.

Just to be sure it's not the operating system (Vista) or the software (Nero 7), I've tried using the recorder built into Windows and have tried using Linux but end up with the same results. One thing to note is that once this happens to a DVD, I can still use it again; it will register as a blank disc in Windows and Linux. The only variable that has stayed constant in my experiment is the DVD discs that I use.

My question is, can it be that my optical drive still works but it's just the DVD's that are corrupt, or is my optical drive no longer capable of burning DVDs? The DVDs I'm using are Memorex DVD-R's and Memorex DVD+R(RW).

 

It could be a dead DVD drive, this is how they usually go, but before drawing the conclusion, try another brand of DVD-Rs

 

That's what I was thinking of doing. It just so happens that the only DVDs I have lying around are some old ones my friend gave me a while back. I'll buy some more and see what happens.

And just incase, how much are external optical drives, do they support USB 2.0 (I don't have FireWire), and what's the average speed of them (read/write)?

Edit: I just finished burning a DVD+R DL full of movies and it worked perfectly. The files also read and play fine. I guess it was just some faulty DVD discs that caused the problem.