I have the same problem, ImgBurn got stucked at 83% three times
(I've only used it 5 times, because I don't want to throw away more DVDs)
writing diferent ISOs (all above 4 GB).
ImgBurn says "writing sectors" but the writing rate is 0.
I'm using a Acer Aspire laptop (plugged in) with Vista Home Premium, 3GB of RAM and a "PIONEER DVD-RW DVRTD08RS ATA Device".