What are the major differences between IE7 and IE8 that a web tester should know?

Question

What are the major differences between IE7 and IE8 that a web tester should know?

Answer 1

We have had lots of CSS issues during testing, especially positioning items in an absolute position (eg images).

Answer 2

You can take a look at this discussion at SO. It takes a look from the developer's perspective.

Answer 3

one major change is that IE8 doesn't center block level items with text-align: center the way that IE7 would. Now you must use display: block; margin: 0 auto;

Answer 4

See http://blogs.msdn.com/ie/archive/2009/03/12/site-compatibility-and-ie8.aspx