That's correct S1mon, it has been that for a while since 0.3d got released. I believe this'll be fixed to RS5 or fixed sooner.
But there are some possibilites to fix this, try to use F4 then write /kill to suicide and change to another skin and another location. If this doesn't work and you will be in an area surronded by grey walls, you need to be teleported out by an administrator+.
If you are stuck and see an administrator+ ingame, ask him for a teleport out and it'll be fixed. But now to the part where your /area will show that you are still inside an interior. To resolve this, write /spawnreset on the place the administrator+ teleported you to and write /kill after and your area may be resetted.
Or you just enter a new interior and the /area will be fixed immediatly and track your current position.