Raener,
Have a look at this
Post
There are a few other post concerning when one can use the pm service.
I think we have firgured it somewhere around 500 post or somewhere around that.
Along with possible length of time that you have been a member,
I will say that I visit a few other help sites with the pm service available and I find it to be a pain ( If your the one doinfg the helping ) The idea of the forum is to post your questions and someone will reply hopefully your problem is resolved, and others having the same issue may find a soluation.
I typically spen my time in the computer, Internet and general forum and to be honest with you have found the need to use the pm service only a couple times,,
This is a very open group here at A2K some pretty much most everything is discussed in the forums,
Hope that helps,
BTW
Welcome to A2K.