We recently upgraded one of our Windows Phone 7 apps to Mango and things went quite smoothly using the Visual Studio’s built-in “Upgrade to Windows Phone 7.1” –functionality.

But when we started testing the app, we noticed that some of our textboxes had a wrong input scope. In one case this made our app impossible to use with virtual keyboard because the textbox was missing the Enter-key.

We had previously defined the textbox using the InputScope “Number”:

<TextBox InputScope="Number"/>

And with out pre-Mango version this was the output:

But, after upgrading the app to Mango, the keyboard was completely different:

The Enter-key was gone, rendering the app useless. We had to change the InputScope to “PostalCode” to get the required functionality back:

So, even if the Mango-upgrade goes smoothly, it’s a good idea to test all the textboxes before submitting your app.

Source: http://mikaelkoskinen.net/post/wp7-mango-inputscope-app-upgrade.aspx