Upload & Sell: On
You should be able to see what mode is the application running in.
If you have a 64-bit Windows 7 or Vista installed then all applications in the Windows Task Manager that are NOT running natively (in 64 bit mode) are marked in the Processes tab as *32. So for example, I have firefox.exe *32 listed there, and obviously it means that the firefox is running in a 32 bit mode, therefore it's a 32bit application, but winword.exe isn't, and it doesn't have the "*32" next to its name.
Did I make this clear?
Now, go and check your Task Manager and run both European and US version to see if there are any differences, then let us know.