I want to have arrow heads at the end of a number of lines. I add these through Line properties --> Line decorations.
It looks nice and all when displayed in the legend:

But in my map, due to different angles it looks more like this:

or this:

The arrowhead is not centered on the line, it is not even at the end of the line! It looks even worse if I have thicker lines (which I want).
I have tried to fix this with adding a displacement, but I can't do that in a direction relative to the line, only relative to the map (x/y directions).
What can I do to fix this? Or is there an alternative way of adding arrows to my map, preferably with my lines as starting ground?
I have noted this question, which to some degree deals with the same issue. Although it is asked for Arcgis 9.3 and the accepted solution is not solving my problem (I want exactly one arrow head for each line feature).