Find my iPhone won't find my Mac

I have two Macs, an iPad, and four iPhones. I have 10.7.2 installed on both of my Macs and I have upgraded both mine and my wife's accounts to iCloud. On both machines I have turned on Find My Mac in the iCloud System Preferences. When we sign in under my wife's account in the Find my iPhone app her Mac and iPhone are listed. When I sign into Find my iPhone under my account I can see my iPhone 3GS, 4, 4S, and my iPad. I can not see my Mac. I've tried turning the setting off and back on to no avail. My Mac will not show up in the app.

Does anyone have any suggestions?