How to disable composite keys on Mac OS X
Composite keys are bound to the 'Input Source' of your mac. 

In your 'System Preferences', in 'Language &amp; Text' you will see the option 'Input Source'.

If you have selected 'U.S. International - PC' for example, you will have the dead key problem. But if you change that to ordinary 'U.S.' you are fine and dead keys won't be a problem any longer.