IE9 problem. the header background is disappeared.

I have tested my times and found that It could be this theme problem.
on IE8,9, the background of header is blank (white)

I thought It was plugin conflicts. But It’s not from a specific plugin.
I have tested 2 servers and 4 multi-blogs with fresh theme(1.4.1) and installed, active plugins 1 by 1.

1. removed all of plugin and started “active” 1 by 1.
I thought revolution slide made it. But it’s not only the problem with revolution plugin. the reason is number 2.

2. I created a new site on multi-site and setup all of them again and started active 1 by 1.
revolution is ok. but next plugin (usquare) made the top header white.
on new multi-site, wordpress-social-stream plugin made the top header background white.

3. I installed new hosting server (even different domain) to check which plugin caused the problem. (I thought It could be my wordpress default setting problem such as wp-options…)
installed 1.4.1 ….etc (all same and fresh one) and started install plugins 1 by 1 and keep checking IE8,9
revolution is ok, usquare is ok, wp-social-stream is ok,… when rtMedia was installed, the top header became white!

4. I also tried to same thing with others. and check 1 by 1.(plugin and themes)
I could not find which plugin causes the problem. because they are all different result.

Can you please check if your theme works fine with IE8,9? I am doing my best to fix it but I can’t really find.
I have tried all fresh theme and plugins with 2 servers.

If you need screen shots or url, please let me know your email address. I will email you.

Thanks,