I bought Mobile air mouse app for iPhone and it works fine when iphone and computer both are connected to same wi-fi network. As they adverties it also works wi

I bought Mobile air mouse app for iPhone and it works fine when iphone and computer both are connected to same wi-fi network. As they adverties it also works with ad-hoc wifi network created from any computer. I tried this in my office, hoping to use iphone as PowerPoint remote control. But it doesnt work. As soon as I try to connect the app to the network, Server Application running on WinXP dies. Sent them few emails, they promised to fix it but then never got reply back from the.