MOST IMPORTANTLY YOU NEED TO DISCONNECT THE BATTERY AND WAIT 15 MINUTES BEFORE ATTEMPTING THIS. If you follow the wires from the seat belt buckle, you will find it leads to a connector block under the front of the seat, the block is held together with a small bolt, unscrew the bold and disconnect, also fiddle with the wires at the back of the connector block, gently pushing them in, reconnect the block and do up the bolt, connect the battery and either the airbag light will not blink, or it will blink with code 3 3, which is the drivers side seat belt buckle, repeat the process with the drivers side connector block - if you are still getting the 3 4 blinking airbag light, repeat the process on the passenger seat, BUT MAKE SURE YOU DISCONNECT THE BATTERY BEFORE ATTEMPTING TO DO THIS. I think the problem is with wires that go into the connector block. It seems to happen when the seat is moved back or forward, but not all the time, its a very very annoying fault with the Jaguar X type 2007, my friend has the 2008 facelift model, and does not have this problem. Since owning my X type for 2 years, I have had this problem twice, which I have resolved, first time having to disconnect the connector block under each seat. The second time I installed new brake discs and pads, and had the air bag light flashing 3 4, I really do not know why the air bag system would have been affected, but it did, with the air bag light flashing 3 4, the second time it happened I disconnect the passenger side connector block and gently push the wire on the back of the block, connected everything back together, connected the battery and the air bag problem had disappeared. Hope this helps you.