Strange, but minor issue with my LDAP plugin

Ok, so I have an LDAP authentication plugin: Simple LDAP Login which can be downloaded here: http://wordpress.org/extend/plugins/simple-ldap-login/

My plugin is primarily/solely constructed around my redefinition of the wp_authenticate function.

Which is all fine and dandy…it works perfectly.

However, one of my users recently noticed that with this plugin installed, the login page initially returns a “Username empty” error on the first visit to the login page, before the button has been pressed or any attempt to authenticate has been made.

I noticed that this is also true of my own installations I just hadn’t previously noticed this behavior.

I spent some time trying to find some place in my code that could cause this behavior but I am at a total loss. My plugin seems too simply constructed to be responsible for a false authentication attempt.

I could try making a generic plugin that redefines this function using the original wp code, but that seems like a lot of work at the moment. My code shouldn’t be executed until “Login” is clicked. It shouldn’t matter *what* is in my function.

Has anyone else noticed strange behavior like this when redefining wp_authenticate??