[FW-1] IKE Between 4.1 SP5 and NG FP2

[Lannon Van Rooyen]

I have set up a tunnel making sure names, config is identical and timings are ok between 4.1 sp5 and NG FP2 firewalls and get the following error “IKE Log: Sent Notification: invalid cookie <phase1>" According to some resources this is a interoperability issue??   Has anyone had this in the past or can shed any light on this? Would be really appreciated   Lannon