Constant Content

I was just wondering about the available file types that show up when you view the detailed page about the individual articles. Now, I know that I've submitted my articles in different file types, but the only one that is listed in the detailed pages next to "Available File Types" is "Text". Is this a bug? Or should I only be submitting one file type from now on? I seem to remember it showing more than one type there before, but it's been so long since I've checked that I'm not completely sure.