Playback problem on verbatim 8x DVD+R



recently bought a spindle of mcc 003 dvd+r’s. Discs burn on both my nec3500 and ricoh mp5125a without any problems, and the nero dvd speed reader gives the best results I’ve seen of any discs I’ve burnt before. I always use booksetting of DVD-ROM for compatability on my standalone player. The problem is that my standalone player doesn’t recognise the DVD’s. It says “unknown disc”. It doesn’t matter which burner I use, I get the same error (I’ve tried burning at 8x and 4x). I’ve not had this problem any any other media (+r or +rw).
Has anyone else had this problem with verbatim 8x DVD+R.
Its especially annoying, that I bought these disks having seen other peoples high quality burning results, and they are the only disks I’ve not been able to play.