Flaming heck - Canons support team are naff.... fireing out random pre done text..... asked about this battery so they mailed me that I have to get my lens fixed at a Canon center /facepalm.
Terran
Thats what they are telling me.... majorly not happy.... had it 3.5 weeks from new !The 450D has a rechargeable one built in I think, it doesn't have a user-changeable one anyway, so if leaving the main battery in for a while doesn't help , the camera will need servicing.