I got this Philips DVDR1620k/00 drive a few months ago. it's comes with Nero 6 i think, have had no problems burning data or video to Mirror DVD+R, TDK DVD-R and Ritek DVD-R, but i got a Verbatim DVD-RW disc, which burnt video fine onto it, but when i've tried to erase it, it's said either that the drive cannot erase the disc, or that the disc is not re-writable and cannot erase, and it IS a rewritable disc! What can be done? should i try to upgrade the firmware or could that cause other problems which are not currently there? Thanks!