Thanks for the prompt reply.
1. Here is the ImgBurn information of the disc that works:
HL-DT-ST DVD-RAM GSA-H50N 1.03 (ATA)
Current Profile: DVD+R
Disc Information:
Status: Incomplete
Erasable: No
Sessions: 2
Sectors: 1,548,576
Size: 3,171,483,648 bytes
Time: 344:09:51 (MM:SS:FF)
Supported Write Speeds: 4x
TOC Information:
Session 1... (LBA: 0)
-> Track 01 (Mode 1, LBA: 0 - 1548575)
-> LeadOut (LBA: 1548576)
Disc Control Blocks Information:
HP DVD
Physical Format Information (ADIP):
Disc ID: RICOHJPN-R01-02
Book Type: DVD+R
Part Version: 1
Disc Size: 120mm
Maximum Read Rate: Not Specified
Number of Layers: 1
Track Path: Parallel Track Path (PTP)
Linear Density: 0.267 um/bit
Track Density: 0.74 um/track
First Physical Sector of Data Area: 196,608
Last Physical Sector of Data Area: 2,491,711
Last Physical Sector in Layer 0: 0
Physical Format Information (Last Recorded):
Disc ID: RICOHJPN-R01-02
Book Type: DVD-ROM
Part Version: 1
Disc Size: 120mm
Maximum Read Rate: Not Specified
Number of Layers: 1
Track Path: Parallel Track Path (PTP)
Linear Density: 0.267 um/bit
Track Density: 0.74 um/track
First Physical Sector of Data Area: 196,608
Last Physical Sector of Data Area: 2,491,711
Last Physical Sector in Layer 0: 0
2. Yes. The player error message is "This type of disc cannot be played. Please insert a different disc."
3. I haven't tried burning at 8x or 12x yet.