sharpening problem

[blacksack]

ok i have one razor (well actually i have 4 but the other three have different shaped blades and dont have this problem)
and im having trouble sharpening the very front of the blade where it curves away slightly the rest of the blade is hht sharp but the tip is still dull i'm guessing it has something to do with the way the edge curves away as the other razor i have has the same shaped blade but doesnt have the big curve at the end and is sharp the full length
is there a different sharpening thechnique i need to use on the point or do i have to file the whole end down to make it flush again?

all help and advice most welcome and i've attached pics to help