Case-sensitive login on WordPress 2.9

I’ve been having this problem with my wordpress installation since 2.7 wich is the first version I used. Login doesn’t work unless the right caps are used. I am aware that case insensitive usernames were implemented in wordpress 2.8, however, I am currently using 2.9 and the problem persists. Unless the right capitalization is used, the logins won’t work. I am using the vbridge plugin for wordpress and I am not sure if it has something to do with it. Is there any way to fix this issue other than just doing a clean install?