Not sure about the D80 - got the manual downloaded but not the camera - but tried the same thing on my D70. Shutter speed set to 30", self timer on. Press shutter release; after 10 seconds, shutter opens for 30 seconds (viewfinder balcked out). With your shutter speed set to 30 seconds, I would expect your shutter to stay open for 30 seconds.
-------------------- MATWSIJ.....
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