I use ubuntu 12.04 precise. I am not able to read written dvds. A blank dvd is recognised and can be written using brasero or k3b etc. but after that if I try yo read that same dvd it still shows blank. Video dvds are simply not recognised at all. This might be an old bug, even but after searching lots of "[SOLVED]" threads problem exists. I tried all the threads, everything in it, like lshw, fstab and all that stuff. No success yet. Pls help