I HAVE A2004 SIENNA XLE. LAST SUNDAY OCTOBER 28,2007 THE LIFT BACK DOOR WHEN OPENED (POWERED ) AND REACH IT'S HIGHEST POINT WHEN ALL OF A SUDDEN IT JERKED DOWNWARDS FORCEFULLY ND HIT MY HUSBAND(-TRYING TO PUT GROCERY). IT SHOULD HAVE STAYED UP. THE MILEAGE IS JUST 17,000+ EVEN THOUGH IT WAS BOUGHT JULY 2004. IT HAS SINCE NEVER WORKED. IT DOES OPEN BUT JERKS BACK DOWN AGAIN WHEN IT REACHED THE TOP. *TR