It could be!!
Number 1 on my 'suspect list' is the N75; Number 2 is the MAP sensor; Number 3 is the remap itself.
I know of only 1 guy who has the same map and almost identical mods yet his ran sweet as a nut on a recent Dynoday. The only difference, my mapper tells me, was the VAG software version that the map was running on and he thinks there might be a quirk that leads to the map requesting lower rail pressures. I only see that at low to mid-range and it doesn't really correlate with where the drop in engine load occurs...unless a similar quirk affects load.
My car goes in for a K04 conversion next week which will involve a completely new remap and N75 (which comes with the new turbo) as well as the injectors. If there is still a problem then I can only think of a manifold pressure problem or a problem with the MAP sensor itself. I may investigate/replace before this time just to satisfy myself
