Post the result of the Nero CD-DVD Speed burst transfer test, you need a disk with some data in the drive to run the test. It should display about 23 MB/sec.
Check the DMA settings of your source and target drive.
2nd: disc quality scans are really slow. also i don't like the results.
This is probably a result of the slow burning you see.
3rd: the benq drive isn't recognised as benq in nero (or windows) but the ricoh drive is. the third drive is a virtual drive (i had daemon tools)
You bought a bulk drive, at least you use a bulk firmware. The drive id name is as usual for bulk firmwares.
4th: uninstalled the secondary, primary channels and the controller (several times) to make sure dma is enabled. defragged my hdd and flashed the 1620 in windows safe mode and still the same results.
Defragging is a good idea. In case your burst rate is ok, check if you have a online virus scanner running on your source disk. NVidia IDE drivers are also known to cause problems. Disconnecting the other drive on the IDE bus might also help.
5th: dvd media are infiniti 16x rated dvd-r mcc 03rg20 burned @ 4x. firmware is g7v9.
i think it might be a defective unit
G7V9 is a bad firmware for scanning, it does not support PIF scanning and might also cause slow scanning (not shure about this). Go back to G7T9.
Edit: Before I forget it, do not burn fast media at such slow speeds. The Benq is best at 8x and above. Lower speeds will produce worse results.