And if you delete the add before .twtr-hd ? Could be the Problem that you copied it too 😀
But is Jetpack working or isn’t it?
This is late, but for all who search a solution for this. Here is mine!
Like Chip said, (thanks for this plugin btw).
Step 1: Install JetPack Plugin.
Step 2: Register
Step 3: Go to Designs/CSS change
Step 4: add .twtr-hd, .twtr-ft {
display: none;
}