did you change the booktype to -rom?
put the burnt disc in your burner , open imgburn in write mode and take a look on the right hand side at the , physical format information ( last recorded )
it should look like this
BENQ DVD DD DW1640 BSRB (ATA)
Current Profile: DVD+R DL
Disc Information:
Status: Complete
Erasable: No
Sessions: 1
Sectors: 3.812.032
Size: 7.807.041.536 bytes
Time: 847:09:07 (MM:SS:FF)
Supported Write Speeds: 2,4x
DVD?R DL Boundary Information:
L0 Data Zone Capacity: 1.944.864
Changeable: No
Physical Format Information (ADIP):
Disc ID: RITEK-D01-01
Book Type: DVD+R DL
Part Version: 1
Disc Size: 120mm
Maximum Read Rate: Not Specified
Number of Layers: 2
Track Path: Opposite Track Path (OTP)
Linear Density: 0.293 um/bit
Track Density: 0.74 um/track
First Physical Sector of Data Area: 196.608
Last Physical Sector of Data Area: 16.580.607
Last Physical Sector in Layer 0: 2.283.519
Physical Format Information (Last Recorded):
Disc ID: RITEK-D01-01
Book Type: DVD-ROM
Part Version: 1
Disc Size: 120mm
Maximum Read Rate: Not Specified
Number of Layers: 2
Track Path: Opposite Track Path (OTP)
Linear Density: 0.293 um/bit
Track Density: 0.74 um/track
First Physical Sector of Data Area: 196.608
Last Physical Sector of Data Area: 16.502.911
Last Physical Sector in Layer 0: 2.141.471
Layer Information:
Layer 0 Sectors: 1.944.864 (51,02%)
Layer 1 Sectors: 1.867.168 (48,98%)