It happens just about once per month. I get an e-mail from someone who has managed to crash their flash card. This can run anywhere from, “It was no big deal.” since they were just testing a new camera to, “Oh my God my Africa trip is gone!”
But in every case I have heard of so far, the problems were avoidable.
1) Always FORMAT your card after you have downloaded the images from it rather than erasing the images one-by-one or taking them en’ masse to the trash. This cleans up the file system and greatly reduces your chance of a crash.
2) Don’t share cards with friends, or put them into other people’s cameras or computers. This can cause a crash since the other camera or computer may attempt to write a system, desktop or file of unknown format to the card.
3) Stay away from the super-duper, neato ULTRA fast and large cards until they have been on the market for six moths to a year. 90% of the problems come from these cards. They use gimmicks or acceleration routines that may or may not work in your camera but that can cause instability. They are also really expensive so that’s plenty of reason to avoid them anyway.
4) The very large (and expensive) cards, are prone to far more File Allocation Table (FAT)-like errors. For ultimate safety, stick with smaller cards until later this year, when the really big cards will be down in price and up in reliability.
I think you’re better off buying four cards that carry “X” amount of data than one great big card that carries the same amount. You will get more reliable results and you won’t have all your eggs in one basket. Remember, if you lose a 16-gig card, you lose all 16 gigs worth of data. If you have four individual four-gig cards and lose one, you still have three/fourths of your data.