[tebasuna51]

With Input Settings: Milliseconds
and load a DELAY 509ms.ac3
I get:

Delay -> Start (msec): 509
====== TARGET FILE INFO ==============
Start Frame -16 (512 ms)
...
NotFixedDelay -3.0000


With Input Settings: Frames, 23.976
and load a DELAY 509ms.ac3
I get:
Delay -> Start (frames): 13 (542.2 ms, incorrect, must be 12 -> 500.5 ms)

====== TARGET FILE INFO ==============
Start Frame -17 (544 ms, incorrect, must be -16 -> 512 ms)
NotFixedDelay -1.0000

If after check Cut file and
Cut File -> Start (frames): 62 (2585.9 ms)
Cut File -> End (frames): 8325 (8264 frames -> 344677.7 ms = 5:44.677)

====== TARGET FILE INFO ==============
Start Frame 64 (2048 ms, must be 65 -> 2080 ms, near to 2585.9 - 509 = 2076,9)
End Frame 10850 (must be 10835 = 10771 - 65 +1)
Num of Frames 10787 (must be 10771 = 344672 ms, near to 344677.7 ms)
Duration 00:05:45.184 (5:44.672)
NotFixedDelay 5.0807

If you check 'Cut File', check also Delay -> 'Original length' don't have sense for me (and maybe for others users).