Can you bust out of it by hitting Control-C? And when you hit ENTER several times, does the screen scroll up with each successive ENTER keypress? Some programs, when you do not provide enough command line options just sit there, waiting for more input. Hitting Control-C can bust you out.
Another problem is that some programs do mess up your terminal session. I'm sure most people have had issues when they exit a particular program, and they cannot see what they're typing at the command prompt any longer. Or, they only get output buffer dumps when they hit ENTER (after the command has been issued, but not getting echoed keystrokes). Often, the only thing to do in this case is to disconnect, and re-login.