by Scoje- » Wed Jun 23, 2010 8:01 pm
You may have the 'Modern Warfare' issue.
Basically on PS3 anyway it wont let you connect with majority of people unless your connection uses NAT2, NAT3 will give you this problem.
A way to check this is, by going to your PS3 and go Settings > Network Settings > Internet Connection Test. The test will take only a few seconds. It should have a category of 'NAT Type'. If it comes up NAT3, then you have the 'Modern Warfare' issue.
Sadly I can't give you a direct solution for this as there are many factors here that could be the issue. I suggest calling up your ISP and asking them how to change your NAT type, hopefully they can help.
Hope this helps!