We use wpmu 2.7.1 and the LDAP plugin.
User blogs are case sensitive. One way it will work completely but if you do different case sensitivity it will not load posted content.
example: http://blogs.district279.org/bensonmelissa/ (works)
example: http://blogs.district279.org/BensonMelissa/ (does not work)
I added the line from http://trac.mu.wordpress.org/attachment/ticket/898/lowercase_blog_urls.patch
However, I still have to test that. Also, what happens if users already logged in, which created their account and blog, will it fix those or will it only work for the users who will log in, in the future.