System Profiler says this:
PIONEER DVD-RW DVR-106D:
Firmware Revision: A612
Interconnect: ATAPI
Burn Support: Yes (Apple Shipped/Supported)
Cache: 2000 KB
Reads DVD: Yes
CD-Write: -R, -RW
DVD-Write: -R, -RW, +R, +RW
Burn Underrun Protection CD: Yes
Burn Underrun Protection DVD: Yes
Write Strategies: CD-TAO, CD-SAO, CD-Raw, DVD-DAO
Media: No
But, if I insert a DVD+RW with data on, nothing happens. Toast knows there's a disk in there but does nothing with it.
If I insert a DVD-RW and try to erase it in Toast I get an error straight away, saying incompatible format. Just tried erasing a DVD+RW and it works!. What the f...
So to conclude, I can read DVD-R. But I can't read a DVD+R. I can erase and burn a DVD+RW, but can't do anything with a DVD-RW. This is all bizarre!