S5 CF card write error
This seems like an unusual problem. I know you have tried a different CF card but have you tried a DIFFERENT brand of card? I have used S5's for years and have never seen this problem
I have looked in my S5 book and cannot find a solution to your problem. It basically says to format the card and try again. Try a different brand of card and try that. If that doesn't work the book says to contact FUJI repair.
Good luck with your problem