What card is it? Since cameras are using these horrid little cards more and more instead of proper man-cards like CF, I've had to start using them over the past couple of years.
I've come to the conclusion they are generally crap. Even big brands.
The only card I trust and would buy now is the new samsung ones - they are really good and unlike the lexar ones I had previously which broke just through use, I've had one of these in a carpark for a week, rained on and driven over (I lost it) and it still worked fine when I found it.
these are the fellas I use in all my SD cameras.
http://www.ebay.co.uk/itm/SAMSUNG-SD...item5ae9237a6d
Always be careful of touching the contacts, you can fry cards easily with a bit of static madness.