C# Simulated click doesn't work when clicking on Flash

Question

Hi,

Made a C# .NET application with C# Express 2008. It's basically an auto-clicker. On my pc everything works fine, but on my friend's pc (new install of windows 7) the clicks don't register when clicking in a flash game. But the confusing thing is that the clicks still work on his pc with other things like the desktop, and windows explorer.

Any ideas why he gets this problem?