I'm using a Pioneer DVR-215, firmware version 1.22, on Windows 7 64bit (with various apps, e.g. Nero, DeepBurner) - to try and burn a simple ISO DVD (tried both with and without multisession).
This used to work for me on WinXP (32 bit) up until a few weeks ago when I switched to Windows 7.
Now, I get a "Power Calibration Error" for speeds 8x-20x, and an "Internal Target Failure" when I set the speed at 4x.
I'm using Verbatim media, which have worked for me before with the same burner, manufacturer ID MCC03RG20.
This all seems like a software/driver issue, even though the error messages regard the hardware. Any ideas how I can resolve it? Also, can it have something to do with 32-vs-64 bit mode?