Try going into the camera menu and selecting memory card then 'format' then OK. In other words wipe your card clean using the camera programme.
If your camera is still telling you that the card memory is full then I suggest you get a new SD card. Even if you upgrade to a 2GB card it will cost you less than £4 from ebay.
Be careful dont be tempted to go even higher and go for a 4GB card unless you are prepared to buy the new HC (high capacity) reader to go with it. An HC reader will cost you all of £6+pp from the same source but still well worth the extra increase in video time.
Cladlyn
August 2008