Some Users have been receiving reports of viewers unable to view videos properly when usign Internet Explorer 9. Symptoms include (but are not limited to) hearing audio but not seeing video. Common causes include:

• The viewer's machine uses Intel HD Graphics Adapters (Included in Most Intel Core i3, i5 and i7 processors)
• The viewer's machine has a (now outdated) version of Adobe Flash installed (10.3 and below)

In most cases, a combination of fixes can be suggested to the user:

• Download and install the latest graphics drivers. [click to update]
• Download and install the latest version of the Adobe Flash Player: [click to update]
• (Not Recommended - Use as a last resort) Disable IE9 and/or Flash's graphics card (GPU) acceleration. Disable IE9 GPU Acceleration [microsoft.com] | Disabling Hardware Acceleration in Flash [macromedia.com]