Wich SMIX mod did you use?
I'm using lastRSS agregator 2.0.0RC on my live forum, only adjusted it to a whole newspage with several RSS feeds. You need to be logged in to view this page so here is a screenshot
I've recently i installed SmiX.MODs Feed News Center 0.4.0 on a testforum, it works but it's very buggy but it works without problems for over a week now. link to that is here
I prefer to use the first one