Textarea height Chrome problem
It's because textarea is a replaced inline element.
textarea { display:block;}should solve your "problem".
The 2px is the standard border size. It's the same across all browsers though.
This works in Chrome, Firefox..
No borders : http://jsfiddle.net/NctDT/2/
Borders and ajusted div height : http://jsfiddle.net/NctDT/4/
In both cases the div and textarea are both perfectly aligned in height.