Canon SD1300IS memory card is locked. I have used this card for 3 years I don't get it?

www.usa.canon.com/cusa/support

SD and SDHC cards have a slide switch along one edge. The position farthest from the metal contacts locks the card, protecting it from writes. The position nearest the contacts unlocks the card.
The position of the switch doesn't affect reading the card, hence no problems loading the pictures from the card to the printer.

There are several possible causes for "memory card locked", "memory card error", or "no memory card". The most common cause is having the tiny slide switch on the side of the card in the wrong position. But, if you've checked the slide switch, the internal switch in the card slot may be jammed by a grain of sand or gunk. Here are troubleshooting steps for this problem. Recommend the toothpick fix for your particular problem.

If your camera is the type that uses SD cards, then your problem is that the camera was developed in 2004 before SDHC cards were invented. Your camera cannot use them.

If your old memory card was "busted" is it possible youhave damaged the memory card holder/reader in the camera?
Anyway, seems memory card problems are not uncommon with this camera.
It might be worth your while to have a look at http://web.canon.jp/imaging/eosd/firm-e/eos
This enables a firmware update which may (or may not) fix your problem.

I suggest you to use a 1GB SD card. Even 2GB might be supported. Don't use SDHC cards. They are incompatible with older cameras.

If this camera uses SD cards then what may be happening is that the little lever that drops into the slot on the side of the card to indicate locked or unlocked is jammed in the locked position. If you shine a flashlight in you might be able to see where the pin is.

Maybe it is having trouble with the size of the memory. Memory cards have grown enormously in capacity in the last couple of years, and even relatively new cameras may not be able to cope with the memory size of the newest cards. It is often difficult to find out the maximum capacity a camera will use, as today's memory cards are much larger that those available when the manual for the camera was written.

SD and SDHC cards fit the same slots, but many cameras won't work with the SDHC (high capacity) cards. SDHC is not backwards compatible.

vebhat,
Make sure the little slide on the SD card is in the right position, and if it's a high capacity SD it might not be compatible with your camera...
randy320sgi

check the pins where the memory card enter, if they are all there (not bended) go to canon site and download the latest framework.

P.S, mack sure to use the right SD Card type as the camera is compatible with some types and with a limited size only.