A querky thing is happening with my new Canon A620 and two new SanDisk 512MB (not super speed but regular) cards. About 1/3 into the card capacity I start getting "Card Error" messages with inability to either record or view recorded images. "Card Corrupted" or "Unidentified File" comes up. Also, a regular card format can be done in-camera, but not "slow format." That comes up every time with "Card Error" and the camera just goes black and shuts down. My other smaller, 64MB and 32MB cards all work fine in all functions, including slow format. So I'm suspecting the Sandisk 512MB cards. Have posted a request with SanDisk Support, but have not yet heard. Thanks to anyone who might recognize something I'm missing.