I've tried Trillian before but it didn't seem to work properly (I could only connect to one service at a time). I think its because it needs a lot of resources and I'm usually using most of my resources.

I don't know of any other clients to MSN that are anywhere near as good as MSN6.. m$ have done a good job with MSN6 and thats a real unusual thing. Which is why I'd like to get MSN6 working if possible :)