There have been problems reported with some Mac and Windows laptops.
Apparently some lap top card readers are not capable of handling a 2 gig memory card. The less expensive solution is to buy a portable card reader, or don't buy 2 gig memory cards.
I seem to remember of one report of a laptop not being able to read a 1 gig memory card.
This type of problem is about to get more common with the entrance of the new 4 gig and higher memory cards.
Memory cards rated at 4 gig and higher are classified as HC ("High Capacity"). The high capacity SD memory cards will have a special logo showing SDHC.
Many (but not all) of the very latest cameras can handle HC memory cards. By latest....I mean that the camera was introduced (announced) within the last 6 months.
Older cameras can not use the HC cards unless the camera maker comes out with an updated firmware that has to be loaded to the camera.
Now here is the big kicker....
Most card readers can not handle HC memory cards.
Before buying a HC memory card (4 gig or higher) you need to do your homework:
...Will it work in your camera?
...Will it work in your card reader?
So get this: last week I'm in Hawaii with my family, taking lots of digital pics with my Casio EX-750 (which I love) on one of two brand new Kingston 2GB SD cards. Daily I would transfer, but not delete, the pix to my brand new Macbook via a portable media card reader.
After taking a series of spectacular (ahem) family group shots atop the Diamond Head crater, my nephew attempts to use the same card reader to download these photos to his Macbook. Most of the pictures download, even ones taken earlier the same day as the family shots, but everything shot after a certain time of day won't download (including the family pics). Kept getting error message that the files were corrupt or in a format not understand. Plugged the card reader into my Macbook, same thing: most, but not all, would download, except the series including the family photos.
Plug the same card reader into my brother's Windows XP laptop, and voila, ALL the pictures download without any issue. Come home, and plug the same card reader into my Windows XP desktop PC, all photos download no problem. Tried to download to my Macbook again, no go. Same thing happened with the other 2GB card: most, but not all, would download.
I didn't have this issue with my 1GB card and my Macbook. Any ideas as to why two 2GB would have issues downloading to Mac and not Windows?