Sigh, what's wrong with my 2Gb SD flash card

Here's what happned:

I was trying to move some files from my Tablet PC to my desktop. I didn't have the public folder of my desktop set up yet, and I just wanted to do it quick, so I tried to use my KingMax 2Gb SD card to transfer the photo folders.

So first I found out that the card was NOT recognizable on my Tablet PC. Then I tried using my EagleTec card reader to connect to the laptop, copy the files to the card, and then copy them on my PC. Unfortunately, when I looked into the files on my PC, half of them were broken.

Eventually I feed up with the card thing, so I set up the public folder on desktop, and the file transfer was all working fine.

Still, I want to figure out which part was the problem. So I reformatted the card, use the exact same way to copy file then read it on the desktop, and guess what? NO MORE PROBLEM?

So it seems like the reformatting solved the problem.