Comment 8 for bug 1022832

I now know how to reproduce it...

When there are more than 4 Important Security Updates. If you see the headline by default, then there's something different. I don't.

What you can do to force the situation:

Scroll down using the arrow-keys. Just press it until you see the headline disappear. Then press it 4 positions back up. As #3 and #4 mentions, the highlighting uses the same solid color as the scroll bar indicator, thus rendering the scrollbar invisible.

There are two parts.

1) Fix Update Manager so the scroll pane is initially at the top, exposing the headline.
2) Ambience bug: The marker should not be able to render the scrollbar invisible.