Sorry for the delay in replying.
I just successfully formatted a first disc with InCD4. I was skeptical about a hardware issue since everything else works fine with this drive so I dived into the installed softwares. Looks like uninstalling Alcohol 120% did the trick. Must be incompatibility between both (odd that it would affect InCD but not Nero itself).
Next thing to try I guess is installing the latest Alcohol trial to see if the problem is fixed (my trial time is expired but it should allow me to install it at least to see if InCD still works). I'll keep you posted on how it works out, this problem could have been fixed since the older trial I had installed.
Just installed Alcohol 120% 184.108.40.2061 trial and rebooted. I'm still able to format with InCD4, so I guess this is an issue that got fixed in a recent Alcohol update. However using the "InCD Erase" Explorer menu seems unreliable. First time I tried it I got an error after InCD stalled for 30-45 secs (no activity on the drive). Second time it succeeded in doing a quick erase. However I just noticed these events in my Event Viewer:
Event Type: Warning
Event Source: PlugPlayManager
Event Category: None
Event ID: 257
Time: 12:25:20 AM
Timed out sending notification of target device change to window of "InCD_GUI_MAINFRAME__1A6E0D67_3515_471D_8D7D_C8E76EC0DA2A"
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp
I guess Alcohol and InCD4 don't like each other.
I'll try again later this week after uninstalling Alcohol to confirm that everything is really 100% when it isn't installed. But so far the problem seems to be with Alcohol 120%.