My Eye-fi card works well in the camera and in the built-in SD readers of my iMac and laptop but when I put the card in the Eye-fi USB SD adapter or in another USB SD adapter Windows or MAC OSx want to format the card. When I tell the system OK, format it both systems gives the error message that the card can't be formatted. With the card in the build-in readers there is no problem.
The problem occures in my vacation house, that PC has not a build-in SD reader so I can not switch the WIFI to another PC or copy files from the card.
Anybody seen this problem before?