Updated Android SDK, now have problems installing apk to real devices

Question

I'm developing a taxi order application for Android. Two days ago I got stuck with a problem that I couldn't use Internet on emulator - it refused to work. The cause was in network settings in Windows, but I learned it later. That time I just tried to reinstall Android SDK hoping everyrhing will be repaired. Before that I was working with revision 16. Now I installed revision 20. My Eclipse ADT plugin automatically updated to support newer SDK version.

Now I work without real device and test everything on Android emulator. Today I sent the newest release of my app to my chief but I refused to be installed. The minimal SDK version is 8 (2.2), and the chief has an Android 2.3 device. He tried to install this app onto other two devices. Another 2.3 device also declined apk, but a 2.2 device accepted it. What's the problem? Note that I didn't set max SDK version. I also tried installing and running my application an a 2.3 emulator, everything was fine.

P.S. Problem solved, see Tim's suggestion below.

Answer 1

If he had an old version installed have him try uninstalling that first. My guess is that you got a new debug key and it is failing install due to different keys.