I have a weird problem with my E71. Occasionally the contacts search where you start typing a name and the contacts pop up filtered on the home screen just stops working. I can get it working again by disabling and reenabling the feature (by typing something and choosing options>contacts search off; then turning back on).
Does anyone know why it is randomly ceasing to work? It's really annoying to sometimes use it and have it not work and then have to disable and re-enable.