Technote from Adobe: Flash Player 10.3 & IE9
When viewing SWF content in Internet Explorer 9 with Flash Player 10.3.181.14 installed, the SWF content will only be displayed in the upper left corner of the screen. The reports for Flash Player 10.3 indicate that systems with Intel HD Graphics adapters running Internet Explorer 9 are the systems being impacted by this particular bug.
Note: If you are encountering this issue and have a different configuration, please review the instructions on this page for details on generating the information we'll need for further investigation.
On some systems, you may be able to resolve this issue by updating the Intel HD Graphics drivers. It has been reported that driver versions 126.96.36.1991 and above do not exhibit this bug. Unfortunately, some systems might require updates directly from your system manufacturer. We're working with system manufacturers to make sure they include the latest drivers in future releases.
You can disable hardware acceleration in Internet Explorer 9 using the instructions on this page. Please note that you should re-enable hardware acceleration once this problem has been resolved to enjoy the full benefits of hardware acceleration.
[A hotfix is scheduled to be released this week]