Perform a cold boot. That means power off the notebook and wait a full two minutes before powering on again. Flushing the system memory in this way often works wonders.
Are your drivers up to date? Check @ Latitude 6500 drivers
I'm afraid Tsh00ter
's comments are largely irrelevant here because Netflix uses Microsoft Silverlight to stream video, not Adobe Flash. In that respect though, you do need to ensure that you have the latest version of Silverlight installed which you can download from here: http://www.silverlight.net/
The latest version of Firefox which is v11 may also be of some benefit to you since it's an up to date browser offering far more than IE8 ever can including support for HTML5.
You can download Firefox from here: Download Firefox 11
Check its features here: Firefox 11 features