Problem burning single layer DVD

NERO 7 ULTRA EDITION

Clone PC
Intel 2.8ghz CPU
1 gig mem
Western Digital 120gig HD. 92gig available

DVD Drive: Memorex DVD Double Layer 16X
Using Memorex DVD-R (single layer) disks
Burning at 4x. Have never tried higher because of symptoms below.

Task Manager on Performance Tab (System Idle)
Physical Memory (K)
Total: 1048044
Available: 717680
System Cache: 672640
Processes: 53
CPU Usage: 0 to 1%
Commit Charge:
250M/2461M

Disc Info under BURN Compilation
It says BOOK TYPE. What does that mean?

HERE IS MY PROBLEM.
IAM USING NERO BURNING ROM

Used Read Buffer:
fills to 100% and after about 3 to 5% on the completed line the used read buffer starts to diminish until it gets to zero then fills back again to 100%. Again after 3 to 5% more on the completed line the used read buffer does the same thing. This process continues until the DVD is finished.
The time it takes to finish writing is double that of the time it states it will take.

Buffer Lever for recorder:
Starts at 100% and as the used read buffer falls to zero and starts fill again the buffer level for the recorder falls between 45 and 65% then fills back to 100%.
(If I burn a DVD-RW at 1X the used read buffer stays at 100% as well as the Buffer Level for recorder).

Can anyone give me a clue as to what is wrong.

Thanks in advance.

Try burning at 8x or higher on your next burn if the media is rated for it. The worst that can happen is a coaster.

The buffer levels usually go up and down like that for me too. I don’t worry as long as I don’t get any coasters. I burn at 8x regurlarly for data disks. Anyway it’s better to burn a little slower unless your in a big hurry. Haste usually makes waste.