There are two options to fix this:

1) The easy fix is to place the following code in your header, just after the ‘title’ tag:
<meta http-equiv=“X-UA-Compatible” content=“IE=EmulateIE7″ />

You’ll find it here:
app/design/frontend/default(your interface)/default(your theme)/template/page/html/head.phtml

2) The best fix is to add some code to your css so that you aren’t making a global change away from IE8, which is going to become the standard whether you like it or not.  Open your iestyles.css file and add the following code:
.pager a:hover { zoom:1; }

You’ll find it here:
/skin/frontend/default/(yourtheme)/css/iestyles.css

Once you’ve made the change, refresh your cache (magento and your browser), and you should have the problem fixed.