If for some reason, you got rid of some important information on your iPhone, whether from third party applications, your photos, contacts, notes, SMS, or call history just press ?debug? on the eclipse menu. Here the widget apk is sync?ed thus you are supposed to install onto your emulator or device. You should switch your eclipse workspace to DDMS mode either by pressing the ?DDMS? labeled button on your top right corner. Ensure that you select the process name of your widget from the list of processes shown and if you select by default, this list appears at top left of DDMS window. Thereafter press the green debug button above the process list and finally you are done. Therefore at this particular time, if you had put breakpoint in the code, do something that executes that piece of the code.
Yes as JamesKK mentioned there is a way to enter a "debug" mode, but it is more for developers. You would have better luck just restoring your phone to factory defaults in iTunes. This will fix your issues and save you a few hours.