I have a Plextor PX-708A for over a year now and it always work fine for me. However, about a month ago, I upgraded the firmware from 1.07 to 1.10 and thats when I started getting problems. At first, when I try to burn something, the LED instead of flashing orange, will switch between orange and green. This cause the burner to take 1 or 2 hours to burn a DVD at 8x. This happen 2 or 3 times so I decided to downgrade the firmware to 1.07 again.
However, now there is a new problem. I can select 8x to burn, but Nero won't burn at 8x. It will say something like "burning started at 8x," but in reality it burns at 4x. The reason I knows this is because it takes 14 minutes intead of the 4 minutes to burn a full DVD. I have WinXP Pro, Nero 184.108.40.206. The DVD media is Ridata, manufacturer code RICOHJPN. PIO Mode 4, ULTRA DMA Mode 2 in BIOS. Device Manager have the drive in Ultra DMA Mode 2.
Also, the Buffer Underun bar is always at 87%, which is the same as before the upgrade.