Default SD Card and sync problems 10.1

I have a Galaxy Tab 2 10.1 put Dhollment Kit Kat on it and tab works fines. The Sd card does not.
It won't stay mounted and when try to transfer to the card keep getting disconnect errors.
Tried fat 32 format and NTSC (ntsc is more stable but not perfect)
The card keeps loosing data and unmounting. It's a 64gb samsung (thought a samsung sd in a samsung tablet would be a no brainer)
obviously not. Also is there a syn manager and back up manager that works best with these since rooted can no longer use
kies which again is a good thing. only thing i used it for was back ups.

any help appreciated also did reboots and hard reboot and still same problem. only thing i noticed is there's a usb debugging message that pops up sometimes. thanks tried to post in the dhollmen rom thread but site wouldn't let me.