Scratch

When I load this project I'm working on, when it is supposed to respond to the keyboard, it doesn't. Furthermore, if I replace the 'wait for "space" key to be pressed' block with a 'wait X seconds' block, it just stays there and does nothing. And I was trying to lanch it by next weekend ('today' is the 13 of September 2009). What do I do?
P.S. I have already tryed saving the project, and reopening. I even rebooted the computer. And the keboard works fine otherwise in Scratch: I can still type in letters and numbers.