I'd used b2evolution for my project, and found some bugs. I haven't find these bugs in this forum, so I post here:

1.
- Create an user, then type a special character (or letter) in User Level textbox and Save
- Or create an user, then left the Login textbox blank and Save
- Or create a blog, then type a special character (or letter) in "Posts/Days per page" textbox and Save

-> these result a Bad Request response. I think it should response error message like "User level must be between 0 and 10."

2.
- Compose a new message, then type the message name "!@#$%^&*()". The message will be compose successfully, but when you view it, there will be an error message like this: "Parse error: syntax error, unexpected '^' in E:\Program\wamp\www\b2evolution\blogs\inc\_core\ui\results\_results.class.php(1023) : eval()'d code on line 1"

3.
- When I run a automation script to create 10 blog with the same name but different in URL, sometimes the blog isn't created (it's pretty random).

I can't perform it manually, but I think you should check it out too.