I use my SD card for my 505 all the time, but when I put it into the 600 the staus circle thingy goes and goes and then the reader shuts off. I did this maybe 3 times with no luck. When I pop it back into the 505 it's fine.

Is it because it's not formatted to the 600? What should I do to get it to start working properly? There are no error messages that pop up at any time, and re-starting the reader is not a problem.
Thanks ladies and gents!