I'm suddenly experiencing problems with my Canon SI IS's memory card. I'm getting memory card error everytime I start up my camera now. It won't let me do an formatting and I've tried a separate card. Yes, I'm putting them in correctly. Does anyone have any idea what the problem is? If worse comes to worse I'll just have to return this and get another one.

If you get the same problem with different cards it suggests the problem is with the camera rather than the card. Although to be certain you'd need to check a card in a different camera - not always easy. If the camera is still under guarantee and you can return it and get another one I'd think that'll be the best solution. Good luck :-)

Go to walmart or best buy and shove your memory card in one of the cameras that you are allowed to play with and see if it works :)

always keep your receipt on cards too, if it is the card you can send it back with copy of receipt and mfgrs RGA and get a new one quickly...

CF cards are pretty robust and don't often fail (although I have had a few go bad on me). Are all of the pins in the card slot making contact and not bent? I have heard of the pins occasionally getting bent and then causing numerous card errors.

That's pretty sucky... I've been thinking about it, and Will's suggestion of checking for bent pins is good. The only other thing I can say is make sure to try the Canon branded card that came with it, and if it doesn't work, try formatting your card(s) directly on a PC or other (preferrably Canon) camera. If the cards work nowhere, then it's a card problem. If the camera works with no cards, it's a camera problem and it'll have to be sent back. :-/

the only time i had this problem was when i bought a cheap, i won't say the name media reader and the pins did break out of the reader and stay in the card, scared the bejesus out of me, and i took hemostats and removed the wire and never had a problem since, beware of price alone...on any thing !

Oh, wow. You're right. I just checked it out and it looks like one pin is slightly off in the camera. This sucks. It looks like it may have even messed up one of the cards itself, but that is yet to be determined.

Problem solved. I returned this puppy to Wal-Mart and simply got a new one. It wasn't exactly noble of me since I bought it from an online site, but I'd rather Wal-Mart be out $400 than me.

you might exercise due care on insertion of cf cards from now on and don't try it backwards, walmart will never be out, they simply return it to canon...