android market - application update does not work

I have a new version of my app on the market and an old one installed on tablet. I expect to see download/install option when 开发者_如何学编程I navigate to the application page on the market but instead I see "open" button as if the market version were already installed on the device. versionCode is incremented in market's version.

What could be a reason for this?

The version of your app installed using adb is probably not signed, or if it is the signature doesn't match the one on the app in the market. First need to uninstall the version that was installed using adb then the market version should install without a problem.