The Nino rpm will simply not work for SME as it is build for fedora. Maybe adding the option --force to the rpm command could do the job, however using this option might get you into troubles. I would not recommend this.
If you really like to install Nino, you will have to revert to the nino.X.tar.gz file. This installation method will require some more manual post installation work, as e.g. the httpd.conf file has to be edited. As the httpd.conf file on SME is maintained by the SME templates, you would have to make a template addition as well. Maybe a bit complicated but it seems to me that it can be done. If I have some spare time left, I might give it a try...
You also might have a look at ntop (
www.ntop.org). There is a 3.0 rpm for SME available. I compiled version 3.1 myself, as 3.0 is very demanding in its memory req.