My SD-M1712 will read DVD+RW discs but only if the booktype is set to DVD+RW. If booktype is set to DVD-ROM, the drive light will stay on after trying to read the DVD+RW disc for several seconds, and the disc is not accessible in WinXP. Whenever this happens, I put the DVD+RW disc back into my DVD burner, use a booktype utility to change it back to DVD+RW booktype, then the SD-M1712 will read the disc properly.
I am using the J004 "no read limit" patched firmware on my SD-M1712.
This is an inconvenience, as the DVD-ROM booktype has better compatibility with DVD players, etc. than the DVD+RW booktype, and more DVD burners are setting the booktype to DVD-ROM by default. In my case, I almost always need to change the booktype for DVD+RW discs just to keep the SD-M1712 happy.