I am having some issues updating my 520.  It was working fine after several previous updates and I went to do the latest update lastnight.  After multiple attempts I now get the messgae "Cannot launch application, please make sure SD card is properly inserted" everytime I turn on the ifly.  I cannot go any farther than that  As far as I know this card only goes in one way and as I said it was working fine before.  I contacted Ifly this morning and they emailed me a "rebuild kit" which I loaded onto the SD card, however I still get the same message when I boot up the ifly.  Their office is closed and I cant get any help from them until tomorrow, but want to fly with this GPS early tomorrow morning.
Does anyone have any ideas or has anyone been through this too?
I am using a Mac desktop computer.
Thanks