I know it says in the handbook if W/L stays on "contact your dealer" but is there any check I can do in the meantime? Don't fancy a face-full of airbag halfway past a lorry on a 90 mph bend.....
If the SRS light is on it means that the airbag will NOT be deployed in the event of an accident so you don't have to worry about the thing going off on its own.
As to what you can do to turn the lamp off, many people on here say disconnect the connector from under the seat and spray with WD40, I personally would be very surprised if this worked as I know a few people who have had a similar problem and the connecter was fine.
Apart from that I can't help you much but say the airbag will not deploy if the lamp is lit (so I am told).