You are not the first person to notice this. Apparently, LG added some kind of riplock with DL12. See this thread for more info (start reading at post #242) :
Ala42 says he will be looking into it, but give him some time. As I understand it, trying to find and remove riplock in firmware is a lot harder than other firmware modifications (e.g. removing region coding) :
If you want to know more about it, try asking him about it in that thread. At least Ala is looking into it. As I understand it, nobody else can be bothered to try removing riplock from LG writers as it is too troublesome.
I don't know why LG decided to put in a riplock with DL12. They never did something like this with their other writers. I want to strangle them too. The thing is, quite a few things were improved with DL12 and above :
- burn quality improved quite a bit with DL12 for quite a lot of media types As Mciahel mentioned above
- DL13 fixed a problem with burning audio CDs with the 4167B. Audio CDs burned with DL12 and below could not play properly on some CD players
- DL13 also fixed a problem with burning TTG02 (TDK 8x DVD-R) discs. DL12 and below cannot burn these discs. The burn process failed and you end up with a coaster if you try.
So unfortunately, you have to decide if it is worth it staying with DL11 because of these changes. If you do not burn audio CDs, do not burn TDK 8x DVD-R (TTG02) discs and have no problems with the burn quality of your discs now, then you can probably stay with DL11.