I assume you're talking about some sort of mobile device like a PDA, phone, or other. An RSS feed is just an XML file. It's just a text file. Generally it's displayed in an aggregator or reader software, or on another web page. It would depend on the software you're using to display the file.
No. RSS is RSS. There are a few different versions out there, but none specified for mobile. It's probably just an issue with whatever aggregator/feed reader you're using. Make sure the feed validates.