Hello to everyone!

It's the first time I write in this forum so  sorry for the basic questions (and for the English mistakes, I'm italian) , I've  tried to find a solution by myself without solution.

I have a quite big iges file (created by pro-e) but when import it the  result is not so good, it miss a lot of things. I have tried with an  evaluation licence of Rhinocers and it translates it very well, I see all  parts and surfaces!!!! Why SW can't do it!!

I've tried to change options in SW: increase the tollerance but no  change, unflag the "try to make the solid" but no change!! I've tried all  the flag on and off all the options.... but the result doesn't change! Does it works??? I would happy  also to have surface but I can do it?

Anyone can give me some tips?

Thanks in advance