Cant Mount SD Card In Recovery

Hey Guys,

Can anyone please help me?
I had a search but cant really find any direct answers,

I had an S2 before, never had any problems, rooting it flashing ROM etc etc,

Just got an S3,
When i first flashed a CWM on it, i think it was version 6.0?
I had no SD card in at the time, after flashing it went to a CWM recovery screen and had a count down from 20 seconds saying "Trying to mount SD Card"...of course there was none inside it at the time , so the timer went to 0 and then reboot the phone and it was back to the launcher, I inserted an SD card, downloaded a ROM,

I then , reboot to recovery, now when i try to use my SD card to install the file it says "Cant mount SD Card",
Tried to go to advanced and mount, still no luck?

I tried to flash 6.1.4 touch recovery, same thing,
i went back to 5.5 same thing,

SD card works fine when i am in windows, or when the phone is on and file explorer,

I just flashed a Stock ROM through Odin and tried again, still no luck,

Someone,
Please help :(

Thanks