If you do not choose a default browser in order to get asked every time you will run into trouble with AppDesTages (I guess similar apps as well, e.g. AppDesAbends, FreeAppADay).
Those apps try to open a website temporarily to access a certain app in the app store. When doing this, the choose-the-browser-dialog is shown for a few milliseconds, but then vanishes. However, the grayed-out overlay-dialog will stay irreversibly. The only way to get rid of it is to hard reset your phone.
If you do not choose a default browser in order to get asked every time you will run into trouble with AppDesTages (I guess similar apps as well, e.g. AppDesAbends, FreeAppADay).
Those apps try to open a website temporarily to access a certain app in the app store. When doing this, the choose-the-browser-dialog is shown for a few milliseconds, but then vanishes. However, the grayed-out overlay-dialog will stay irreversibly. The only way to get rid of it is to hard reset your phone.