Setup: Open long page with a textarea; for this example, use http://bugzilla.mozilla.org/show_bug.cgi?id=12345. Click in the "Additional Comments" box. Tap the spacebar a few times. Correct functionality. Click in one of the input lines above it, and tap the Tab key until the textarea gets the keyboard focus. Now tap the spacebar. Expected: Space inserted into the textarea. Actual: Space inserted into the textarea, and the entire page scrolls down. Build info: Running 4/24 build on MacOS 9, G4/350 Yikes.
I think this is a duplicate of #35952 *** This bug has been marked as a duplicate of 35952 ***