Left-clicking a .deb download link produces a blank dialog and "freeze"

To reproduce, just left-click a download link for a .deb (in my case, the link for downloading the Ubuntu Tweak .deb from either http://ubuntu-tweak.com/ or https://launchpad.net/ubuntu-tweak/+download ). You'll be greeted with a blank dialog window like the one pictured, and Midori will lock up until this dialog window is closed and no download will occur.

Workaround: Right-click the link and select Save As from the right-click menu instead.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: midori 0.4.3-1ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-19.31-generic 3.2.12
Uname: Linux 3.2.0-19-generic x86_64
ApportVersion: 1.94.1-0ubuntu2
Architecture: amd64
Date: Wed Mar 21 17:03:25 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120201.1)
ProcEnviron:
 TERM=xterm
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: midori
UpgradeStatus: Upgraded to precise on 2012-03-11 (10 days ago)