"Recent" tab disappears behind Recent panel when sliding up

[Matthew Paul Thomas]

Ubuntu 14.10 r203

1. Navigate to the keypad screen of the phone app.
2. Very slowly, slide up the tab from the bottom of the screen.

What happens:
* A "Recent" tab slides up to reveal itself.
* As the Recent panel itself slides up, the tab wobbles up and down by a single pixel.
* Once the panel reaches half the height of the tab, the tab disappears behind the screen.

What should happen:
* The "Recent" tab remains fixed to the top of the panel until it reaches the header.