connecting to parties on cod world at war ps3

[#1]

Hi,
Does anyone else have trouble connecting to another plus net users party on the ps3 on call of duty world at war?
I am able to connect to someones party who is not with plus net but I know 4 other people on plus net and can not connect to their party.
Any help would be much appreaciated.
Thanks
Keith

[#2]

[Moderator's post by Jim (Oldjim) Please don't double post - thread locked in favour of http://community.plus.net/forum/index.php/topic,76247.0.html ]