Thanks for both of your suggestions.  I've read about Verbatim, are they that much better? 

@Moth3r: #2 is unlikely, as this is the same type of disc that came in a bundle which I had burned one in about a year ago.  #3, I don't see a filter driver load option in ImgBurn.  Does this mean I have an old version?

Thanks again - I can easily see this being what vbangle said though, as this is a standard crap DELL burner.

hehe.  Yup, indeed.  So then I must be up to date.

OK, figured out I'd previously denied Imgburn internet access for whatever reason.  Fixed, and upgraded.  However, the burn button is still grayed out.  I don't understand why though, because I HAVE done it before - from the same pack no less.  I doubt 2/3 of a 3-DVD pack would be shiny coasters before I even mess up burning it.  On a probably somewhat related note, DVD+R is the only format I have had success with even though I have one that should do both.

Trying a different disc from the same pack did me no good.  It appears my computer is not reading the media at all, like it's incompatible with DL discs.  I know it is for a fact though, because I have definitely burned one before.

Sorry this is so late, I haven't been home.  Yeah, it's +R DL.

Also, recently successfully burned a single-layer DVD.  So I don't think it's a hardware issue, just this computer being itself =/

Yes.  I deleted all of the Sonic ones, but left the Microsoft ones intact.  Still says "Medium Not Present" - and the computer agrees with it.  Looked up my computer specs (Dimension E510), and it should definitely be able to burn dual-layer +R DVDs.  Maybe I'm just unlucky.

Forgive the double post, but is it possible that it's just the  media? These discs have been sitting in my closet for at least a year, unburned...

Bought a new pack of Memorex just out of curiosity.  Definitely not the media - not a single one from this pack has even been recognized by the computer.  Thinks the drive is empty.  I would accept that my computer can't burn them if I hadn't been successful previously.  I can't fathom WHY it says "medium not present" on both imgburn and the computer itself.  Somehow I don't think Verbatim would help with this situation, however I'd gladly upgrade to those once I figure out what the heck is wrong.

As useless as I'm sure this will be, I'm gonna contact DELL.  Thanks for trying guys.

I'd do that, but I'm pretty sure this thing has a warranty and opening it up to install that would void it.  Plus, *technically* it's not mine, it's the family's - and convincing them to upgrade is not an easy task.  Also, it appears mine is SATA.

Here's an image of my filter driver load order, in case this is the problem, someone else might be better fit to analyze it:

EDIT: This is probably important... appears to not be reading anything at all now...

Lucky you, being free of windows.  Yup, overwrote the drivers (since it said I was up-to-date, but I didn't wanna take a chance).

EDIT:  The drive is only reading blank single-layer DVDs, not even regular CDs.  This seems to mean there's something funky with the way the computer is using the drive... I really don't want to re-format over something like that, but I may have to.  I've uninstalled the drive, only to have Windows re-install it and give me the same problem.

EDIT DOS:  At the suggestion of someone else, going to see what happens if I load a live Knoppix CD.  If that's okay, then windows is effing up.  If not, I need a new burner.

Edit 3:  Well, it's reading CDs in Knoppix, but not blanks.  I'm guessing that's a limitation of the live CD.