In fact, this is not a IE9 problem, in the past, there are similar problems in IE8. The solution is simple:
Open IE9-> Press ALT-> Select Tools-> Internet Options in the displayed menu bar-> Select the Advanced tab-> find "Always ClearType for html*", and then restart the IE9 browser.
In fact, Microsoft started by default to open ClearType technology from IE7. ClearType, a technology that appears in Windows XP, improves the clarity of text on a flat panel display. By default, this feature is turned off.