This drive is a piece of crap! In fact most of the new 16x DL drives have the same problems due to them 'disliking' the media you use.
To prove it isnt me or my PC here's my story.
Using Nero 188.8.131.52
One month ago....
NEC 1100a DVD burnt ANY 2.4x or 4x with NO coasters.
Two weeks ago...
NEC 3500 16X DVD fitted in its place, EVERY burn was a coaster... so sent it back and got....
LITEON 1633s... fitted it 2 days ago... I now have 10 coasters out of 11 using 3 different types of media from datasafe reds to datasafe grey to Infinity white 8x.
I also tried some at 4x ... guess what? more coasters.
All the data or video files apparently copy OK, but the session & the disk are left open... even though the 'no multisession' and 'finalize disk' buttons were ticked. Neither the session nor the disk can then be subsequently closed.
Also, if you tick the 'verify' option the verify takes FOREVER.
I burned a DVD of 4.2Gb in 6 minutes... the verify took 45mins!
When it finally finished, I got the message 'Data Verification Started'???
Naturally, the disk upon visual inspection appeared to have successfully burned, it was unreadable either in my PC or my DVD player.
I got my RMA number this evening but just before I removed the drive I thought I'd try a another couple of disks with different software...
NTI 6.5 didn't recognise any of the DVDs
Roxio Easy CD & DVD Creator 6.0 with 'smart burn' ticked burned my FIRST perfect DVD.
The smartburn feature slowed the burning speed of the Datawrite grey down to 4x. The DVD plays in my PC and my home DVD player.
I then tried the same type of disk in nero and manuallt set the speed to 4x.
Guess what? Yip, another coaster!
This proves (in my mind) the problem is with the drive or the software, or both.
I'm certain these 16x DL drives have been rushed out to meet the Christmas market.
They should not be allowed to justify their poor performance by claiming we dont use the 'recommended' media (always the most expensive)
Imagine when the first cassette recorder hit the shops if you could only use recommended cassettes!! You stick in a top quality TDK cassette, but the manufacturer says "If you look at our website you'll see we only recommend Maxell tapes".
I wish I hadn't sold my old 4x NEC. I only upgraded for the speed, not because I wanted to burn Dual Layer... but these two drives have only given me HOURS of misery.
As a final postscript... to prove to myself it wasn't me or my PC that was causing this, I borrowed a friend's LG 8x DVD burner.
Used 3 different blank DVDs and all 3 are PERFECT copies.
I know loads of people in the in the Ebuyer review pages have raved about both the NEC 3500 and the Liteon 1633s, but there are just as many having MAJOR problems such as those in this forum.
The most popular drive according to sales and reviews is the NEC 3500 16xDL drive.
However, try typing these words into Google... 'NEC 3500 burning problems'
You'll get around 30,000 results... and its the best one!
I reckon its down to whether your 16x burner was built on a Monday or not. It's a hit or a miss if yours will be one of the working ones.
Please feel free to shoot me down in flames if you have a solution to the general 16x burning lottery... my drive goes back to Ebuyer on Monday