I upgraded from `python-mode.el-6.1.2` to `python-mode.el-6.1.3` and my `M-x virtualenv-activate venvname` no longer activates the virtual environment in my emacs `*Python*` buffer. This same keystroke used to load the virtualenv. 

My process for updating python-mode was only...

```
$ wget https://launchpad.net/python-mode/trunk/6.1.3/+download/python-mode.el-6.1.3.tar.gz
$ tar -zxvf python-mode.el-6.1.3.tar.gz 
$ emacs init.el

```

And then changing

```
; python-mode
(setq py-install-directory "~/.emacs.d/python-mode.el-6.1.2")
(add-to-list 'load-path py-install-directory)
(require 'python-mode)

```

to the correct folder of:

```
; python-mode
(setq py-install-directory "~/.emacs.d/python-mode.el-6.1.3")
(add-to-list 'load-path py-install-directory)
(require 'python-mode)

```

Then reloading with `M-x load-file`

This is the only change I made that I can attribute the sudden change in behavior to. Anyone have similar experiences or pointers for what might be going wrong?