Always on top - Not anymore!!!

Question

Ok, I have a pretty simple C# application that runs in the systray. I have included some functionality that allows the user to always have the application in the foreground. However, on one particular system this functionality doesn't appear to be working. I was hoping that someone would be able to provide me with some assistance / troubleshooting steps I can take in order to determine what is causing the problem. Any assistance would be greatly appreciated. Thanks, Bob