Okay, I just bought one of these to replace another LG burner that I have had for over a year that was starting to get burn errors about every third disc. After installing it last Friday, I updated the firmware to J03. On all but TY unbranded DVD-R’s I am getting this ring on the burned discs. To be more specific there is an area from the hub out about half an inch that is a light colour. The area from there out to the edge of the disc is a darker colour. The discs seem to playback fine with no issues. In the past I have never been concerned with errors etc. The true test as far as I am concerned is whether the disc plays from start to finish with no issues. I have only had 4 discs (right after a burn) over the past year (of VERY MANY burns) that I have had to toss out due to them freezing on playback. Also, of all the discs I have burned I have never found one (even the ones over a year ago) that has deteriorated. They playback fine. Since Friday I have tried Verbatim DVD+R (Taiwan MCC004), Maxell DVD+R(Taiwan), Maxell DVD-R (Taiwan), Fuji DVD+R(Taiwan), Fuji DVD-R (Taiwan), Fuji (TY) and of course the TY discs that are unbranded. All but the unbranded TY’s have this ringing happening. Should I be concerned about this? Oh, generally the burn speed is 4x for all discs but the Verbatim because I bought most of these in bulk quite a while back and consequently their top rated speed is 4x or 8x. The Verbatim I am burning at 12x. Also, I used PowerProducer V3 to burn the discs.
Do you get the ring for discs burned at 4x? From what I know, the rings are usually caused by LG’s Z-CLV (Zoned CLV) writer strategy for 8x/12x burns. The writer starts a burn for those at 6x constant, and then suddenly ramps up to 8x where it stays for the rest of the burn. For 12x burns or 8x media, there will be another step up to 12x from 8x later. The different areas the writer burned at different speeds tend to show up as rings. It doesn’t seem to affect burn quality though. I’ve had quite a few discs like that with my older 4163B. It never happens with TY media though.
Here are what I found for my H10A burns:
4X CLV (TYG01, MCC002) - no rings
8X Z-CLV (TYG02, MXLRG03, MCC02RG20, MCC003, MBIPG101RG04 and CMCMAGE01) - no or very faint ring at start of burn which I presume they correspond to the starting 6X write strategy. The only exception is a TYG02 which experienced a speed drop from 8X to 6X resulting in quite a noticeable ring.
12X Z-CLV (YUDEN000T02, MAXELL002) - the change from 8X to 12X is noticeable. My previous 12X burns with the 4167 DL12 using the same media also showed such ring.
8X and 12X P-CAV (MCC004, PRODISCR05, CMCMAGM01, RICOHJPNR03) - no noticeable rings.
16X P-CAV (TYG03, MCC03RG20, CMCMAGAM3, PRODISCF02, OPTODISCR016, RITEKF1, MCC004, CMCMAGM01, PRODISCR05) - Rings are present in all 16X burned media with the exception of CMCMAGAM3.
Thanks for the replies. This would explain why I am getting the rings on most of the discs and the not the unbranded TY’s which I am burning at 4x just because that is the top speed they are rated for. I feel better now, thanks. 
Why are the burn rings present on 16X P-CAV?
sorry for digging up the “solved old-ish” thread.
Sometimes it’s the media itself. I’ve found rings on TTH02 (TDK 16x DVD-R) burns on my 4163B (at 12x, which is P-CAV) as well. The same rings apear when the discs are burned even on a BenQ DW 1640.
No rings on anything I have burnt so far, all at 8X, MCC02RG20 and some Sony media, so I guess I’m lucky?
Don’t think it is really an issue. It’s not as if the rings affect burn quality at all. So I doubt this is something you need to worry about.