Dear Sirs, Osprey4 and Glendalf81,
As I have said, I had purchased a new LG Drive to overcome this problem as I had feared that My Sony drive was damaged. But the problem persisted. Again, this problem has surfaced only 2 months ago. Earlier I had burned many dvds with my sony drive without any problem. It was usually multisession and the Nero 7 disc info gave true disc usage information always. In fact even now once in a while( once in 4 to 5 tries) Magic iso still recognses the dvd with true space information and even writes to it. But most of the time there is an error while verifying the written data, so I have almost abandoned the idea of using XP2 for the time being and burn dvds to store extra data through KB3 burner of Linux. I have almost copied most of the data stored in dozens of dvds and now in a few days I am thinking of wiping off/formating total machine and then try once again and see what happens.
I have even updated and installed intel's latest BIOS just in case it might help. But ofcourse no help.
Thanks for repllies and I am hoping to find a bulls eye answer through all of yours guidance and help.