Thankyou, that worked a charm.

I'm having trouble getting back to the shape of my original extruded spline though.

My old extruded spline was a basic oval shape extruded by ExtrudeNURRBS at about 20m.

When i select all the edges of one of the Caps polygons (the front side of my previous extruded spline), convert through 'edges to spline' and then re-extrude using extrudeNURBS by 20m i get a 3d-looking 2d image.

Here is a link of what i mean:

http://img405.imageshack.us/img405/7066/screenshot20110812at251.png
(i panned the camera angle to show how it's not 3d)

Could you please share some advice on what i have to do to get the spline to extrude just out into 3d space and not out and up like in the picture?

I hope that i make sense this time :)