Heavily retarded (!) on full throttle / very low rpm !?

[RomChip200]

I have a trouble that doesn't occurs on full acceleration in the high rpm range:
When accelerating from 3000 to 6000rpm from partial to full throttle, the right timing values of my table are reached: 23° @ 15psi @4500rpm

But when accelerating on full throttle from very low rpm (1500 / 3rd gear / pedal floored), it goes till a point where the timing is heavily retarded and really doesn't match my timing table, there're more than 6° missing !!
It doesn't correspond to any retarded table.
My knock timing = regular timing.
I suspect it has to do with the knock learn region but I don't detect the knock:
My bin is instrumented to monitor knock_count variable @0x14BD and to detect when switching to the knock timing table (bit2=0 when knock map is used in flags @0x5A).
When detected, I switch on the dashboard engine light. And during my tests, no light. I ran unleaded 95 in the past (100% E85 now) and the light went on very quickly on full load (too much advance / octane rating), then my routine works.
I don't monitor knock_inc @0x14CF yet.

Have a look to the pic and the corresponding log file.

Any thoughts ?

[Matt]

what about disconnecting knock sensor and replacing with resistor? that would get rid of knocking theory

can you attach a log file for this one?

[RomChip200]

Log file is just below the pictures:
NIStune_2009-08-22_2209_46.csv

what about disconnecting knock sensor and replacing with resistor? that would get rid of knocking theory

can you attach a log file for this one?