DVD-R Ejects, does not recognize

[Nettoda1]

I have purchase DVD-R Sony and as soon as I insert the Disk it ejects it right away with out any information or any reason why it was ejected, should I return the disks or what should I do, I need to record a 2GB movie from my Imovie, Thank you very much for any help that I can get.

Nettoda1

[CanadaRAM]

Does your machine have a DVD burner?

[Nettoda1]

yes it does ! What is weird to me is that it doesn't tell me anything it just ejects it, this DVD-R is a 120 min 4.7 GB/Go