Remmina Won't Maintain Multiple RDP Sessions at the Same Time

I typically need to connect to multiple windows machines over RDP at the same time (rdesktop was able to do this). However, with Remmina, as I connect to an additional Windows machine, it disconnects me from the other one that I'm currently logged into.

Every once in a while, I can maintain connections to two Windows machines (at the same time), but never 3.
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ApportVersion: 2.0.1-0ubuntu13
Architecture: amd64
DistroRelease: Ubuntu 12.04
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
NonfreeKernelModules: wl
Package: remmina 1.0.0-1ubuntu6.1
PackageArchitecture: amd64
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 3.2.0-31.50-generic 3.2.28
Tags: precise running-unity
Uname: Linux 3.2.0-31-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom debian-tor dip lpadmin plugdev sambashare sudo
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ApportVersion: 2.6.1-0ubuntu1
Architecture: amd64
DistroRelease: Ubuntu 12.10
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
NonfreeKernelModules: wl
Package: remmina 1.0.0-1ubuntu8
PackageArchitecture: amd64
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 3.5.0-17.27-generic 3.5.5
Tags: quantal running-unity
Uname: Linux 3.5.0-17-generic x86_64
UpgradeStatus: Upgraded to quantal on 2012-10-04 (2 days ago)
UserGroups: adm cdrom debian-tor dip lpadmin plugdev sambashare sudo