While my generic sucked badly - I was able to return it, so I was only out shipping. I then got a TOPRAM 4gb card - and have had very good luck. In the 2 months since I've had it, I've only had to reformat once because some data got corrupted. But otherwise, it's running strong.

I've got maps for GPS, movies, music and video games on there. I'm crossing my fingers that this card will stay reliable, but Topram has good warranty service. They were going to accept my old card for repair until I figured out how to reformat it - in a Treo of all things.