Alright, I haven't had this problem before I downloaded messenger plus live.  I'm not saying it's causing it, I'm just saying it'd be quite a coincidence if it wasn't. 

Every time I add someone as a contact I have some kind of problem.  Either they can't add me, or we won't see each other online when we are, in fact, online.  And every time I add someone or they add me I never can add them to my contact list.  It says "To add them to your contact list click here" and nothing happens when I click.  Because of this I can never see when they're online.

Help please!

Doesn't sound like an issue that would be easily resolved by anybody on this forums, it sounds like more of a problem with the server you're connecting to if I'm honest.

I would try speaking to MSN support (at the official Microsoft address) to see what the problem is, they'll probably be able to resolve it, they are afterall experts on most matters like these.

You may want to check out this thread, which seems to have a similar problem with the contacts not showing online (there's also a solution posted in the thread).

Thank you so much!  I used the registry file he posted and it did the trick!