ps3 blue ray not loading BDs ?

[AquaPython]

so this happened twice in a row.

i have seen probably 15 - 20 BDs on the PS3 at this point.

got one in last week, it would not load. cleaned the disk, (no knicks/ scratches), still nothing.

sent it back to netfliz - got a replacement. that one worked fine.

then next on the list was terminator: salvation. same deal, BD does not load. no icon in the system to select and play it.

sent it back, got a replacement - same deal. will not load. i did a system update, still nothing.

is system update the same as firmware update with these? any other ideas?