In fact all unit tests are running on Zope 2.7.7 with Plone 2.0.5.
Zope 2.7.7 with Plone 2.1 bundle fronts an issue in CMF and/or 
CMFFormController and/or [Zope|Plone]TestCase. Read about the problem at
http://article.gmane.org/gmane.comp.web.zope.plone.archetypes.devel/5093
It means 3 failing testsm but its a testcase environment problem, not an 
archetypes issue.

Running unit tests on Zope 2.8.x: Plone 2.1 bundle does not look nice,
loads of deprecation warnings produced from zope, two unit tests are 
failing non-critical because of minor enhancements in 2.8. 
The first is rendered ReST-Text, which is displayed different and therefore 
an assertion fails.
The second fails because a class name is in 2.1 a full dotted path (was just 
the name before).