I have seen this behavior on Windows with Ruby for a long time. If I install a gem sometimes the command line will just get "lost" and stop printing output until you go back to the command line and hit enter a few times.
I notice this in other places too. Like starting up a Ruby on Rails console. Or generating a model with Rails.
Have other people seen this? What causes this? The weird thing is this doesn't happen all the time.
I have never seen this with PHP, Lua, Perl or Python from the command line.
I have seen this on Vista and Windows 7 (32-bit and 64-bit). This happens on multiple machines.