Inventor Fusion

[#1]

Please install the latest Inventor Fusion 2013 and see if the issue is still there

http://labs.autodesk.com/technologies/fusion/downloadform.

And could you give some information about your gaphic card?

[#2]

Hi Sally Graphics card Nvidia Quadro 4000

[#3]

Have you tried Inventor Fusion 2013 yet? And if that doesn't help, please delete the Fusion user configuration files with below steps:

1. Input "%appdata%" in Run

2. Goto "Autodesk"

3. Delete Inventor Fusion related folders

Hoping that works!