Errors on DVD-RW

I am using Verbatim DVD-RW disks, and am trying to copy a 350MB .avi file as data - ie, as a DVD-ROM. I’m having two problems. First, and most important, Nero refuses to burn it. It stops almost immediately, and the last error messages are:

Invalid disc
Unable to recover TOC
Could not perform start of disc-at-once
burn process failed

Secondly, I checked the disc info, and it confirmed it is a DVD-RW. So I tried to erase it - which I suppose you can do with an empty disc. At which point, it fails, with the error mesages “This is not a rewritable disc and therefore cannot be erased.” As you can imagine, this is beginning to drive me mad.

I have two DVD writers - a Plextor PX-708A and an LG GSA4040B, both with the latest firmware. I have the same problems with both drives. I have tried starting a multisession and having no multisession - nothing makes any difference. All I am trying to do is burn 350MB of data to a DVD-ROM, but I’m clearly doing something wrong. If anyone can tell me what it is, I’d be grateful.

(Incidentally, the same file burns fine to a CD-R - haven’t tried CD-RW)

Thanks

Oops - sorry for wasting time! I have now taken a random selection and discovered that all of a delivery of 50 Vertbatim disks are faulty. None of them can be burned. Apologies.