[pabscars]

Have you tried disallowing the game to boot from start up?

Then allowing your console to boot up, sign in as usual to PSN then when its finished loading all your friends online status, then boot the game up.

Did you say you had installed the complete game onto your HDD, took me about an hour ish.

Some of your problems sounds like NAT issues, but I've noticed occasionally GT5 online can be flaky, not just for me but my friends also (on BT BB)

Have you tried allowing the console to connect in "auto" mode because I found messing around with it can make it worse, especially with things like duplex, mtu, etc etc.

Do you tend to play with the same friends a lot, if so have you tried hosting or letting someone else host just in case one of your friends has the NAT issue.

Just a few things youve probably already tried, but just for kick's is there anything interesting mentioned in your modem log.

Have you made sure all the connections are done up nice and tight on the coax from outside to inside, I've noticed some engineers have a habit of leaving them finger tight (soz guys but its true)

Have you tried different ethernet cables

The funny thing is I had some of your issues with Black Ops as in it would take an age to sign into the BO servers, 5 to 10 mins but since I changed to the SH that aspect has been fine.

Good luck