having v7 problems

[jackdogmax]

i have tried to mod 3 different v7's with 3 different magic 3.1 chips and get the same result every time. they will play ps1 backups and originals, backed up movies on -/+ dvdr's, and ps2 originals. they won't play ps2 backups. i know the backups are good cause they work in a v10. i am using tdk dvdr- and dvd+r.
i am using a nec 1300a burner with nero 6 (not express).the ps2'2 are all scph-39001 but with 3 different mobos gh-017, gh-022, gh-023. any thoughts or help would be greatly appriciated.