Using a screen protector with the 770 may interfere with the ability to launch the thumb keyboard by pressing with your finger on the screen.

If you prefer to keep your protector, you can also configure the thumb keyboard to launch from the rocker key (the middle key of the directional pad). Open the application menu->Tools->Control panel->Text input settings, and check the option labeled "Launch via rocker key" on the last tab. This option is also handy for example when web browsing, as hitting small single line text areas with your (fat ) fingers can be tricky at first.