A few months ago I posted a question about the "network incompatibility error 717" issue that was plaguing some of our regular racers: How to fix "network incompatibility error 717" on GT5
This was answered (thank you Tom Wijsman) and people who followed the instructions have never had any problems since.
Recently we've had a bunch of new people start up racing and from the second week on they started encountering "error 749" problems (I am not sure the exact wording of the error but I believe it says something about network incompatibility.) I pointed them to the 717 question but the answer given doesn't seem to have fixed things for them.
Is 749 a different problem? How can they fix it?