Friend List ProblemFollow

I recently have been experiencing some problems with my friend list. Whenever i make a new 'friend' and we add eachother to our friends list, on my friends list it will say that they are offline, even though they arent(i know this because they are talking to me) on there friends list it says that im online. So is it something that im doing wrong? here is the process i use.

/befriend <name>
wait for registration acceptance thing and approve.
Accept and Add.

Some friends it does show that they are online and some it dosent, can anybody help me with this?