If it's an older camera it may not accept a card of a size above certain limits -- see camera spec or manual and see if it mentions a size of card -- that may have been the largest made at the time the camera was released..
Problem can also occur if a card of any size has previously been used in another camera or device. In that case you need to reformat the card in the Canon.
The thing is that I bougth this camera on Ebay iand it came working just fine, after a few minutes, when I opened the case to change the memory card (Compact Flash), stoped working. So, I'm not sure if the problem is the card or the camera because it's not when I put the card in, the problem occurs when I open the case to insert the card, the camera turns off, and then after inserting the card, when I close the thing and try to turn the camera back on, it says (ERROR). PLEASE HELP ME!!!!