Thank you for your post.
I am having difficulty locating a Windows 7 Home Premium computer. The only Windows 7 machines that are available to me are Window 7 Ultimate. On those Windows 7 Ultimate computers, I have QuickTime 7.6.9 installed, and all of the videos are displaying correctly. Do you have the most recent version of QuickTime loaded?
Anything else you can provide to help me replicate the problem would be appreciated.