Opera is often set to indentify itself as:
Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)
Opera 7.11 [en]
In your Best Browser graph this is no problem. But in the
"Details" list an IE-icon is displayed instead of an
Opera-icon.
To fix this bug just change the order in your
ReturnImgBrower function (move opera down in the list)!