I have the NEC 1000A DVD +RW/+R. I have burned several disc's and they all work fine in my NS900V & Panny RP91. I have only used Fuji blanks in both +R/+RW format. Have you tried these disc's in a different player?
My blanks are also purple in color. I'm getting a bit confused here. Do you have a -R/-RW drive or a +R/+RW drive? There are a few drives that support BOTH media types. But you must match the media +/- with the drive type.