Pencil line thickness gone when exported


I came across a pretty annoying problem. I’m doing character animation and using the pencil tool for the outlines. When working in the toonboom display, I can clearly see that there is a variation in the thickness of the lines, as in pointy at the end and becoming thicker towards the middle, which is exactly what i need. The problem however; lies in the export. When I export the layer to .SWF and open it in After effects, the lines have all transformed to 1 thickness. This takes all the sharpness out of the drawing…
Can anybody help me with this?

I have added screenshots to illustrate the problem.