Lion: Use spacebar to scroll or page

In Lion, using the space bar to scroll doesn't work very well - or, sometimes, at all. Even if it just worked a moment ago, in the same page.

Here are a few workarounds I've discovered:

1) Click in the area you want to scroll (ex: within a web page) and then press space.

2) Press the down or up arrows and then press space.

3) This is weird: Press a shift key and then press space!