"Successful Burn" isn't really successful

Okay, this one has me baffled.

For the past couple of months, I haven't been able to make working CDs
with Nero 6, Roxio 6, etc. They seem to burn, but they don't work
afterward. The scenario seems to go like this:

I'll make a new CD image and drag some files into it (or I'll burn
straight from a pre-existing bin/cue or iso image) and then start the
burn. Everything proceeds like it used to (all of the buffer levels
look right, etc.) and then it says that it's finished.

I take the CD out, look at it, and I can *see* that the disc had info
burned onto it. However, when I stick it back into the drive, it
doesn't show any files on the disc. There are a few symptoms that
indicate that the disc is still blank, and a few that indicate that it
is *not*:

"Blank" symptoms:
- When I put the disc in the burner, Windows pops up with the "Blank
CD" "What do you want Windows to do" dialog, where I can tell Windows
to launch Nero, etc.
- When I go to "My Computer" and double-click on the drive (which
isn't showing any disc label), it gives me a "Please insert a disk
into drive E:" dialog.

"Non-Blank" symptoms:
- When I try to burn to the disc again with Nero or something, I get
a message saying that the disc isn't blank and that I need to insert a
blank cd.
- In Nero, I can click "Disc Info" and it shows me the disc showing
one session and one track.

The same bin/cue set that I'm wrestling with right now burns fine on
another machine. In Nero's "Disc Info" screen for the *working* disc
(burned on another machine, mind you), the info for Session 01/Track
01 reads:
Track 01: 0:02.00 20:41.11 (182MB), ISO 9660/ bootable (mode 1)

while the one for a *NON* working discs reads:
Track 01: 0:02.00 20:41.11 (182MB), Data (mode 1)

Now, this seems to happen no matter if I use Fireburner, Nero 6, Roxio
6, or Alcohol 120%. Also, the only CD-related thing I can remember
doing any time around when this problem cropped up is that I installed
Alcohol 120%.

Any ideas?

- Joe