Have you tried burning at 4x or 6x? Try a lens cleaning disc on that drive, and if it still doesn't work, then you may want to get the 2.4x Verbatim blanks or a new (external) burner
I tried burning with 4x speed. It got to 50% but then gave me an error. I used a 8x Verbatim disc.
Here is the log:
I 20:46:08 ImgBurn Version 2.5.0.0 started!
I 20:46:09 Microsoft Windows Vista Home Premium Edition (6.0, Build 6001 : Service Pack 1)
I 20:46:09 Total Physical Memory: 3