Dropdownlists Creates Postback On Key Changes In IE?

I have created a label and a dropdownlist. The label has the dropdownlist as associated id.If I click on the label and then uses the mouse up or down the dropdownlist creates a postback for each click. This is quite anoying and doesn't happen if you click on the dropdownlist and uses key-up or key-down, or if you uses another browser than IE.Is it possibel to fix this, so you can use key-up and key-down without causing a postback, and first on the enter-key creates the postback (as it does if you click on the dropdownlist and not label)?