Hi, I never had any problems with SD cards until I got my D610 in addition to my D90. I'm finding when I switch cards between the two cameras it seems to be doing something funny to the cards. Yesterday my card read 0 on my D90 (even though I had reformatted it in the D90) so I had to put in the D610 which then said it had loads of room for photos??? Any idea what is going on? Should I reserve cards for ONLY either or? Thanks.