OK I just bought a new burner, as I thought it would fix the problem... LG BH12LS38
I still can't burn @ 6x on Verbatim 6x Certified Media but at least it's doing 4x instead of 2x with my old burner.
Here's the log:
I 17:16:10 ImgBurn Version 2.5.7.0 started!
I 17:16:10 Microsoft Windows 7 Home Premium x64 Edition (6.1, Build 7601 : Service Pack 1)
I 17:16:10 Total Physical Memory: 6,216,800 KB - Available: 4,483,400 KB
W 17:16:10 AnyDVD can interfere with ImgBurn's ability to verify accurately, please ensure it's disabled!
I 17:16:10 Initialising SPTI...
I 17:16:10 Searching for SCSI / ATAPI devices...
I 17:16:11 -> Drive 1 - Info: HL-DT-ST BD-RE BH12LS38 1.00-D3 (D:) (ATAPI)
I 17:16:11 -> Drive 2 - Info: ELBY CLONEDRIVE 1.4 (V:) (SCSI)
I 17:16:11 -> Drive 3 - Info: HL-DT-ST DVDRAM GE20LU10 FE06 (W:) (USB)
I 17:16:11 Found 1 DVD±RW/RAM, 1 BD-ROM/HD DVD-ROM and 1 BD-RE!
I 17:20:44 Operation Started!
I 17:20:44 Building Image Tree...
I 17:20:44 Calculating Totals...
I 17:20:44 Preparing Image...
I 17:20:45 Contents: 107 Files, 18 Folders
I 17:20:45 Content Type: BD Video
I 17:20:45 Data Type: MODE1/2048
I 17:20:45 File System(s): UDF (2.50)
I 17:20:45 Volume Label: CPE
I 17:20:45 Size: 22,912,616,252 bytes
I 17:20:45 Sectors: 11,187,865
I 17:20:45 Image Size: 22,914,138,112 bytes
I 17:20:45 Image Sectors: 11,188,544
I 17:20:46 Operation Successfully Completed! - Duration: 00:00:01
I 17:20:46 Operation Started!
I 17:20:46 Source File: -==/\/[bUILD IMAGE]\/\==-
I 17:20:46 Source File Sectors: 11,188,544 (MODE1/2048)
I 17:20:46 Source File Size: 22,914,138,112 bytes
I 17:20:46 Source File Volume Identifier: CPE
I 17:20:46 Source File Volume Set Identifier: 40AA8A9600AAB879
I 17:20:46 Source File Application Identifier: ImgBurn v2.5.7.0
I 17:20:46 Source File Implementation Identifier: ImgBurn
I 17:20:46 Source File File System(s): UDF (2.50)
I 17:20:46 Destination Device: [1:1:0] HL-DT-ST BD-RE BH12LS38 1.00 (D:) (ATAPI)
I 17:20:46 Destination Media Type: BD-R (Disc ID: VERBAT-IMe-000)
I 17:20:46 Destination Media Supported Write Speeds: 2x, 4x, 6x, 8x, 10x, 12x
I 17:20:46 Destination Media Sectors: 12,219,392
I 17:20:46 Write Mode: BD
I 17:20:46 Write Type: DAO
I 17:20:46 Write Speed: 6x
I 17:20:46 Hardware Defect Management Active: No
I 17:20:46 BD-R Verify Not Required: Yes
I 17:20:46 Link Size: Auto
I 17:20:46 Lock Volume: Yes
I 17:20:46 Test Mode: No
I 17:20:46 OPC: No
I 17:20:46 BURN-Proof: Enabled
I 17:20:46 Write Speed Successfully Set! - Effective: 26,973 KB/s (6x)
I 17:21:00 Filling Buffer... (40 MB)
I 17:21:01 Writing LeadIn...
I 17:21:02 Writing Session 1 of 1... (1 Track, LBA: 0 - 11188543)
I 17:21:02 Writing Track 1 of 1... (MODE1/2048, LBA: 0 - 11188543)
I 17:41:44 Synchronising Cache...
I 17:41:48 Closing Track...
I 17:41:49 Finalising Disc...
I 17:42:01 Exporting Graph Data...
I 17:42:01 Graph Data File: C:\Users\Medellia\AppData\Roaming\ImgBurn\Graph Data Files\HL-DT-ST_BD-RE_BH12LS38_1.00_THURSDAY-MAY-10-2012_17-20_VERBAT-IMe-000_6x.ibg
I 17:42:01 Export Successfully Completed!
I 17:42:01 Operation Successfully Completed! - Duration: 00:21:14
I 17:42:01 Average Write Rate: 18,031 KB/s (4.0x) - Maximum Write Rate: 26,991 KB/s (6.0x)
If you need more info, don't hesitate to ask.
Cheers!