Can't burn to different brand DVD-R disks

I had been burning to Verbatim DVD-R disks (16X, 2hr, 4.7GB), and everything worked fine. When I ran out of disks, I bought a pack of Imation DVD-R disks (16X, 2hr, 4.7GB), but the computer won't write to those Imation disks. I keep getting "error writing to disk" messages or the like. The same problem occurs with all three of my DVD-burning software applications, i.e., they all worked fine burning to the Verbatim disks, but they are all now choking on the Imation disks. The answer is probably a slam dunk, but right now I can't figure it out. I've made no other changes to the computer, either hardware or software. (I am running Win XP on a Pentium 4 platform, 1.8GHz, with two USB2 external DVD burners.) Can anyone offer me a suggestion?

 

First port of call is to slow the write/read speed down to say 4* and see if this works otherwise consider returning the disks. Is this with only one particualr DVD or several???? Could be what you are trying to burn has protection and is causing the prob.