Rendering PROBLEM! Light with segments!

[DMZGraphic]

First of all sorry if I had choosen the wrong category! I'm new!

I have a problem. I'm rendering a jacuzzi (made by me) with neon and very cool light... when I render it the light looks like segment, they are not clear object.
Also the bathtub edge it's not clear and smooth... I tried everything, max size for the render, all the values max but I cant.

This is the photo of the external neon of the jacuzzi and the bathtub edge. It's a part with max resolution (1920x1085).

http://imageshack.us/photo/my-images/836/immagineperforum.jpg/





Uploaded with ImageShack.us


I'm workin on a iMac 27".
Can you help me? I'm using keyshot for 3 days so I'm not an expert!
This project is very important for me!
Thanks to all!

P.S. Sorry for my English, I'm italian!