thought I should give an update.
I flashed 7811921 just fine - i had the DSC/ABS warning light after finishing, but went away when I took the key out and started the car. didnt have to use DIS.
but since I have a E90 320D 163ps, i dont have DPF - so I've had the DPF warning light on my dash all day. I couldnt find a way to get around this so I've reverted everything back!
but i must say the car felt different with the D3 software on, quite nippy. if only i could find some way to disable the DPF warning...
are you guys sure about the safety of the D3 software? i'm sure they used spec'ed up hardware too in the D3 from what i've read..