I am running a TC75 with DW 3.1 40
Note that a carriage return and an enter key are 2 different things.
If I go into my profile under the Keystroke output section and select Basic data Formatting/Send ENTER key, it seems to work fine for me. I tried this in the email app and in the chrome browser, it seems to work OK. Is this the way you are trying this? What app are you trying to feed the keystrokes into?