Thanks for the help and suggestions. I will try to use some higher quality media.
I'm slightly skeptical, though, since I have successfully made burns to the same series of media. In fact, I have working DVDs that came from the exact same pack of disks!
Oh well, unless you can think of anything else I'll try another brand - and then resort to calling Dell. I'm not too hopeful with Dell, though, since my warranty just happened to expire right before the DVD burning problems began!
If I do have to get a new burner, any recommendations? I have plenty of SATA slots available or can use the current interface. Thanks in advance.