Few decent burns with nec 3550

I bought my unit in december and since that time i recorded dvd from 4 diferent brands: Patinum(CMC MAG. AE1), TDK(TTG02), Verbatim (MCC) and Sony (SONY D11).
These scans where made at 8x mostly.
I’ve tried the original and modified firmware.
The machine is a PIII 800 with 512 ram. Everithing seems to be alright in the bios. I instaled a new ide cable for the dvd unit(its working alone in the secondary channel)

“verbatim advanced azo+ 16X dvd-r” recorded at 8X:

Platinum:
at 2x

at 4x

At 8x

The only good dvd media seems to be MCC (for my unit), am them TDK. As for the platinum, i burned 25 and no more then ten had aceptable PIF(below 12, with no high red peaks).
TDK is the second most reliable so far for me.
At “safe” burning speeds i get these results, i dont know if i can do anything about it.
This woldnt be a problem if i only had MCC ones, but i have 20 more from sony!
Any tips to make this unit more tolerant?

Here’s a controversial suggestion for you. Since the NEC 355x/455x are not always reliable scanners, you can try to scan one of those seemingly horribly burns at 12x speed instead of 8x speed, and afterwards also scan it at 1x (it’ll take an hour). Then see how it looks.

Why?

I have a number of NEC scans done at 5x and 8x with unmotivated random PIE and PIF spikes, that simply don’t show up when scanned in a Plextor or LiteOn drive, and which usually don’t show up in a 12x or 1x scan in the NEC drive.

I bought a new LiteOn SHW-1635S almost entirely based on its more reliable DVD scanning than the NEC 4551!