My PX-716A have the same problem~~ 
Accdording to the CD dump guide, if the first audio track's pregap is 2, LBA-149, then move left to the last sector of the data track, it can't be read except you eject the driver then colse to read again.
I think it's a bug of PX-716A.
For the diferent binary: you can use CDtool, "ECC off" checked, then you can obtain the data track from ISObuster with 716A, matched your PX-B950SA.
That's my trouble too~~~~~http://forum.redump.org/topic/12513/psxnew-japan-x2/
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