4051 interfacing

Hello

I’ve been trying to interface the 4051 demuliplexer to arduino duemilanove.I followed the tutorial from the playground and got it working actually almost working.The problem is that when I turn a pin high the voltage on that pin will be about 1 volt not 5v as I expected. :o
I don’t know what is the problem…can anybody help me with this please?

can anybody help me with this please?

Sure. Show us the circuit you have created and the code you have written.