different gwt-textbox height in IE9 and FF13

[tong123123]

I found that for gwt-textbox (without modify any of its css attribute), when render in IE9, the height is 22px but NOT including padding-top, padding-bottom, border-top-width, border-bottom-width, so in IE, the gwt-textbox is in fact 22+1+1+1+1 = 26px;
but in FF13, the height 22px is including padding and border, so in Firefox, the gwt-textbox height is really 22px.

why has these difference?