Toilets, Sinks, Showers, Tubs and Disposals - Shower head problems

When I turn on the water to my shower like all showers it comes out the faucet first. You then pull up the lever to make it come out the shower head. Here's the problem. When I first turn mine on, everthing works like it's suppose to, but after a minute or so, even if I don't pull up the handle water starts coming out the shower head as well. When I do pull up on the handle, water does shut off to the faucet and comes only from the shower head. Can ya tell me whats wrong and a possible fix, Thanks

What brand of faucet? Single handle? Dual handle? Diverter on tub spout?
Mike

It's a duel handle and the diverter is on the spout.

It could just be that the pressure in your house is a little high. The only thing that keeps water from rising to the level of the shower head in this type of arrangement is that the free flow into the spout drops the pressure inside the pipe to a level that water does not rise to the head. New showers of this type usually have a restrictor in the outlet to the shower to further improve the situation. Other than lowering the pressure, the only other thing is to make sure the spout is not gummed up in any way. Possibly replace the spout.

Thank you very much for the replies. I give them a try and let you know ho they turn out.
Thanks again