Unmaximized windows snap to bottom when dragged offscreen

Steps to reproduce:
1. Drag an unmaximized window partially off the bottom of the screen.
2. Mouse over the "Window List" applet.

Expected behavior:
Nothing should happen.

Actual behavior:
The window snaps up to the bottom of the screen. Furthermore:

3. Drag the window such that it is entirely within the screen.
4. Mouse over the "Window List" applet again.

Expected behavior:
Nothing should happen.

Actual behavior:
The window snaps _down_ to the bottom of the screen.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: gnome-session-fallback 3.2.1-0ubuntu8
ProcVersionSignature: Ubuntu 3.2.0-31.50-generic-pae 3.2.28
Uname: Linux 3.2.0-31-generic-pae i686
ApportVersion: 2.0.1-0ubuntu13
Architecture: i386
Date: Sat Sep 22 14:42:36 2012
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release i386 (20100816.1)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-session
UpgradeStatus: Upgraded to precise on 2012-08-25 (28 days ago)