package link in the index file is not correct
For example, the links to the tarballs of Flask in the /<root>/simple/Flask/index.html are:
... <a href="../../packages/source/F/Flask/Flask-0.8.tar.gz#md5=..." ...
while they are actually located in ../../packages/source/f/Flask/Flask-0.8.tar.gz . Please be noted the case difference: It's a lowcased f, not F in the real path.
This problem result in installing failure: a 404 error