I've got a Pioneer A07 (107), and have burned a DVD Backup on DVD-R and DVD+R media. Firmware was 1.05, burns were at 2x/2.4x
the +R media worked in my Sony 7000. The Media was Ricoh JPNR01 (fuji & memorex).
the -R media didn't work in my sony 7000. This media was RitekG04 (ritek) and TYG01 (Fuji).
Interestingly the -R media was read by more of the DVD-ROM readers that I have than the +R media.
My next test, I want to take these 4 dvd's to a best buy/good guys and just try them in a bunch of players.