My home page looks fine in IE8, IE9, FF & Chrome, but in IE10 it's all flush left. Is there something special about IE10 that would do that?
It is usually caused by css compatibility. If you want to make your site compatible to ie, then don't ignore microsoft guide http://msdn.microsoft.com/en-us/library/hh781508%28v=vs.85%29.aspx
Without seeing the site in question, that's effectively impossible to answer in a meaningful fashion.