The right column of my site keeps jumping to the far right before correcting itself.

I have this on the css stylesheet:

#navColumnOneWrapper, #mainWrapper {
margin: auto;
}

#navColumnTwoWrapper,
margin: 0;
}

#navColumnOneWrapper, #navColumnTwoWrapper {
margin-left: 0.2em;
margin-right: 0.2em;
}

Driving me nuts trying to figure out how to fix this. Please help! Thanks