Pioneer 110 => unable to read toc

Hi everybody, I hope that someone can give me some help…
I’ve just bought a pioneer 110d (flashed with latest firmware 1.22) and I have a lot of problem with dvd-r.
I insert them in the tray but it doesn’t recognize them at all, I can’t write them with any software like nero or Alcohol. I’ve tried verbatim,traxdata,philips.
It goes with emtec and dvd+r.
Thanks for the help, I hope there is something to do before taking it back to the store.

Do you have Any DVD (or simular) running at startup?
If so disactivate any dvd,should solve the problem.