connecting to another plus net users party on cod world at war on 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]

Add me ITFCdan , and try one night , im on most evenings. I've got a buddy on PN , no probs with connecting to him. 

[#3]

sould'nt be affected by an isp to who you cant connect to.
Not being able to join some peoples rooms is just about allways to do with your NAT or there NAT.
Double check your port forwarding on your router or even better place the ps3's ip address in to DMZ but make sure your ps3 is the only hardawre that gets the DMZ ip address