When getting width, innerWidth, height or innerHeight on an element with a border (5px in this example) the returned value is incorrect (http://jsfiddle.net/Zs92Q/1/):

||= Border Size =||||= 0 =||||= 5px ||

|| Firefox || Width || 50 || 49.83333999999999 ||

|| || Height || 50 || 49.83333999999999 ||

|| Chrome || Width || 50 || 50 ||

|| || Height || 50 || 50 ||

|| Opera || Width || 50 || 50 ||

|| || Height || 50 || 50 ||

|| Safari || Width || 50 || 50 ||

|| || Height || 50 || 50 ||

|| IE7 || Width || 50 || 49 ||

|| || Height || 50 || 49 ||

|| IE8 || Width || 50 || 49 ||

|| || Height || 50 || 49 ||

|| IE9 || Width || 50 || 50.019999999999996 ||

|| || Height || 50 || 50.019999999999996 ||

It appears that jQuery v1.3.2 was the last version that returned the correct value of "50".