I followd your steps exactly and it worked. (I am using C2.1 though) I did get a dialogue asking me if I wanted sweep or envelope. I used an illustrator file. Try using an illustrator file and when you save it, make sure you save it as a low version number (I chose 4.0). Carrara will not recognize files from higher versions (7, 8, 9, 10). I'm not sure if this is your problem but give it a try. If all else fails, do it in Carrara. A 90 degree line should not be that hard to draw in Carrara. Why knock yourself unecessarily importing things that dont have to be imported in the first place? Also, if you're trying to create a pipeline, make sure you set the extrusion method to "pipeline". You hadn't mentioned that you did that in your steps.