door open warning light problem

my freelander td4 5 door on a 53 plate intermitently shows door open warning light when they are closed (interior light on aswell). Also the horn beeps when you lock it. have had it checked and all door switches reading ok. any ideas greatfully appreciated as it is slowly driving me mad.

don't forget there is a switch on the bonnet and boot, and it also checks if the rear tailgate window is closed

thanks i,ll check that out.