Why won't other people's twitter names come up when I use @?

[Cody]

It's just started happening recently. When I type in the @ symbol people's twitter names would come up for me to select but they don't anymore. There's just a blank area where the names used to be. Please help. There's no way I can remember everyone's twitter names and type them in manually
Like I said this just started. I know how you type the first letter after the @ but no matter what I type in nothing comes up. The drop down box is completely empty.