As I thought, called Xbox Support who narrowed it down to a "communications error between my modem and my friends modem". In other words, we don't know and we are going to blame your ISP.

Problem still ongoing....

Both mine and my friends Xbox 360 have all the ports forwarded, they are both in the DMZ and they both have open NAT. We have no problems joining games, chatting to others or joining other parties yet, we cannot chat to each other or join each others party.

Please don't suggest that it is something to do with the ports, the NAT or the DMZ as I know it isn't.

is anyone else having these issues as I am loathed to call Xbox technical support as they are useless?

Cheers

I have a PS3 and a 360.

I've only recently just started to get into the PS3 even though I've owned it for over 12 months.

I have to now admit that the PS3 kicks the 360's ass. I'm not trying to start a system war here, just trying to justify my post.

I played Left 4 Dead on the 360 a couple of days ago for the last time.

This game wouldn't look right on the PS3. It doesn't look right on the 360. The graphics are dated and washed out. The gameplay is too simplistic.

Its a dated shooter that you can have a lot of fun on.

I honestly believe that after playing Killzone 2, COD 4 & 5, Battlelfield BC etc then PS3 owners would be completely disappointed in L4D.

The only place that L4D should be is a user created Mod for Half Life 2 on the PC

No. AS far as I am aware, cross-game chat isn't on the PS3.

It's one of the things that is superior on the Xbox 360.

If it is on the PS3, someone please tell me how its done.

You asked the question, these guys bothered to answer it.

You've obviously only asked so that you can start an arguement.

I own both systems and own MGS4 for the PS3.

People who say that MGS4 couldn't be done on the 360 are completely wrong. There is nothing in MGS4 that couldn't be done on the 360.

If you look at the majority of multi-platform titles, the reviews state that they run smoother and look better on the 360.

I'm not slagging off the PS3, but it isn't the king of consoles at the moment with the current software on it. It "might" have the potential to become the better console though but that would mean that Sony would need to get their act together and stop screwing up!