When you use the keyboard arrow keys or you use a pointing device to scroll horizontally in Windows Internet Explorer 9, the rate of movement may be noticeably slower than when you perform the same procedure in Windows Internet Explorer 8.
This behavior is not as noticeable when either of the following conditions is true:
You disable the Use smooth scrolling option. To locate this option, click Internet Options on the Tools menu, and then click the Advanced tab.
Or, you use a pointing device that uses MouseWheel messages to scroll horizontally.
This problem occurs when a pointing device uses keyboard messages to scroll horizontally. This occurs because the scaling that is used for keyboard-based horizontal scrolling is set to a lesser value in Internet Explorer 9 than the value that was used in Internet Explorer 8.
To resolve this problem, install this update.
Security update information
To resolve this problem, install the most recent cumulative security update for Internet Explorer. To do this, visit the following Microsoft website: