Hi Melanie,
I’m having the same issue. I’ve turned off all other plugins and still only seeing a capitol “T” where my feed should be. I’ve tried with my client’s twitter username as well as “nytimes” and still only “T”.. If i deactivate the oAuth plugin i get “Please install the oAuth Twitter Feed Plugin and follow the theme documentation to set it up.” (which makes sense.. just including it for inclusiveness)..