Panasonic have been making some kick ass digicams recently, with ludicrously good features and optics for the prices. However, this comes somewhat at the expense of build quality.
A commonly reported problem with the FZ5 is the lens becoming stuck in one position. This is because the cogs that drive it are made of plastic and the mounting for the lens motor is a bit flimsy. A Panasonic service centre will charge quite a bit just to look at your camera, let alone fix it, yet this is a relatively simple thing to fix if you’re not afraid of dismantling things.
Of course, you do this at your own risk, not mine. I can’t offer any guarantee that this will work for you, but a few people have had the same error and performed the same fix successfully. Work carefully and it should be fine. This may also be applicable for similar panasonic compacts, such as the FZ7.