An Error from a smart phone from an SD micro card

Question

I had a 4G micro card in my palm phone, and it worked just fine. I put it into my unkles Blackberry and it worked fine. I then put it into a diffrent computer to put more music on it, then took it out and put it back into the Blackberry and it told me this media error. I took it out and tryed to put it in the original computer, and put it back into the blackberry and it still wont work. What can i do to get it to work again??