The code below solved all the problems with IE8 compatibility (problems with styles and some vB functions not working properly like the "quick reply button").
Note: I'm running vB 3.6.x
^Insert it in "headinclude" (AdminCP > All Style Options > headinclude)
Note: I'm running vB 3.6.x
PHP Code:
<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />