Optiarc AD-7173a - no overburning?

Sorry, no feedback at SonyNec Optiarc site. I have very new 7173a. And I faced up with big problem.

No probems wrighting DVD. No problems wrighting CD-RW. No problems wrighting CD-R without overburn (except reading speed no bigger than 40x, though writing speed - 48x - littlebit strange).

I have tested overburn using Nero and Nero said I can write 82-00 minutes. But - no! It is wrighting with no errors but last tracks are not readable. I use TY and Phillips CD-Rs - all the same.
When I use CD-RW - all ok, readable!

Why I can write CD-RW with overburn but cannot write CD-R with overburn???

I checked Phillips CD-r on other PC with Optiarc 5170a - all ok without any errors. My optiarc 7173 is new, I used it for recording no more than 15-20 times…

The Nero test screen after burning is attached. All 3 times test results are absolutely same (as in attached picture). When usind CD-RW - normal result without any strangeness…
I cannot understand: is my drive not perfect or - what???

PS: previously I used NEC-3200 and did not have any problems with overburn and readind speed…

PPS: This is readable disk test but also looks very strange! (PIC 2)

Please give an advise who knows something about this problem…

Welcome to the forum.
Very strange reading graphs there.
The NEC/OPtiarc drives i’ve tested all support CD-R overburn. That does not mean your drive is faulty, it could be media related or some other system issue.

The firmware on your drive is outdated I’m not saying this is the prob but still

Yes, graphs looks strange. I used Tayo Yuden Verbatim and Phillips CD-r - the graphs are same for both CD-Rs with strange down near 69 minute…
Wrighting without overbern graphs are ok.

I dont think it is due to original firmware…

This is result of quality test for DVD-R.
I don`t know how to treat test results just question - is it good or is it bad?