LG GSA-4165B DL04 and RICOHJPNW11 = 2,4x only

I have very strange problem with LG GSA-4165B (DL04 firmware) and TDK DVD+RW (RICOHJPN W11) media.

I’m using Nero Express 6.6.0.16. The media is certified at 4x speed, and my private LiteOn 1633S burns it without any problems at 4x speed, but the LG drive allows only 2.4x speed (the 4x speed isn’t even shown!).

I have tried Media Code Speed Edit, but it shows 4x and 2.4x speed for the RICOHJPNW11 media in DL04 firmware, so why the drive doesn’t allow to write that media at 4x speed?

Any ideas?