This is what I did - with Flirc GUI closed, I ran flirc.exe sensitivity 0, then unplugged the USB key and put it back in, opened Flirc GUI, erased the right directional key, re-learnt it and tried in XBMC. I repeated the same process with every sensitivity level
With sensitivity 1, the remote just doesn't work. With 0,2 & 3 it seems to make no difference and a single press results in 3-4 jump in steps