Tox proves this works everwhere I need it to.

+[tox]
+envlist = py26-django15, py27-django15, py32-django15, py33-django15,
+          py26-django16, py27-django16, py32-django16, py33-django16
+
+[testenv]
+commands = python setup.py test
+
+[testenv:py26-django15]
+basepython = python2.6
+deps = Django==1.5
+
+[testenv:py27-django15]
+basepython = python2.7
+deps = Django==1.5
+
+[testenv:py32-django15]
+basepython = python3.2
+deps = Django==1.5
+
+[testenv:py33-django15]
+basepython = python3.3
+deps = Django==1.5
+
+[testenv:py26-django16]
+basepython = python2.6
+deps = https://github.com/django/django/archive/master.zip
+
+[testenv:py27-django16]
+basepython = python2.7
+deps = https://github.com/django/django/archive/master.zip
+
+[testenv:py32-django16]
+basepython = python3.2
+deps = https://github.com/django/django/archive/master.zip
+
+[testenv:py33-django16]
+basepython = python3.3
+deps = https://github.com/django/django/archive/master.zip
+