WordPress MU

What are the differences between plugins in mu-plugins/ and plugins/ ? Alternately, how do I turn on debugging or otherwise view error output?

I have wpmu installed and running and the ldap plugin works great, but I would like the individual functionality of the standalone wp ldap plugin. So, figuring "i can use the wpmu-ldap plugin for site-wide authentication/blog creation and then use the standalone-ldap-wp plugin for individual blogs (that the blog owners could manage after I enabled it)" I tried putting in the standalone-ldap in plugins/ and activating it, which works (as does enabling it per-blog) but configuring it throws me to an error screen that says "Are you sure you want to do that?" and a "Please Try Again" link that sends me back to the config page for the plugin.

1. I'm sure you know the difference between those 2 folder. As far as I know, there is no different in term of plugin itself (the one work in mu-plugins will also work in plugins).

2. If I want to debug, usually I will put some :

echo "<!--$var_name-->";

somewhere in the place that I want to debug.

You may also need to check the plugin code for the access level stuff.

I'm curious how you were able to get the LDAP plugin to work. Everytime i search for a user, I get 'user' not found. I'm wondering about the syntax of Search DN and User DN for searches. How did you enter those?

sorry I haven't replied to you sooner -- I just saw this!

SearchDN I setup as OU=My OU Name, DC=sub, DC=domain, DC=tld
UserDN is just a username (short version, not username@sub.domain.tld or DOMAIN\username)