Disclaimer: The Reset Internet Explorer Settings feature might reset security settings or privacy settings that you added to the list of Trusted Sites. The Reset Internet Explorer Settings feature might also reset
parental control settings. We recommend that you note these sites before you use the Reset Internet Explorer Settings feature.
Since the issue does not persist in ‘Safe mode with Networking’, then let's put your computer in a
clean boot. Putting your system in clean boot state helps in identifying if any third party applications or startup items are causing the issue.
I would also recommend checking to ensure you have the latest video card driver from the manufacturer.
The fact that the issue disappears in Safe Mode tells you that another program is causing it.
Clean boot troubleshooting will help you identify the guilty program. Clean boot troubleshooting can take some time, but it's not terribly difficult. Try it.
How to troubleshoot a problem by performing a clean boot [Vista - Win 7:] http://support.microsoft.com/kb/929135