It appears the button images within My Conversations (when viewing a conversation) have had the tops chopped off.
This is what the buttons at the top look like...

This however is what the buttons at the bottom look like...

So the ones at the top need to match those at the bottom.
And also, the "Compose New" button on the main My Conversations summary screen has also had the top chopped off.
p.s. Like it was in Beta 1, the symbol on the "Delete" button is still blurry.