Help! Computer's gone crazy

Has anyone had this problem?
I load a raw file in NC, I adjust WB eposure etc I save as Jpeg. The thumbnail looks ok I open the Jpeg in PS and I get this...
I get the same thing if I open the file with NC so it looks like NC is not saving the file properly.
Can anyone shed some light on this?
I load a raw file in NC, I adjust WB eposure etc I save as Jpeg. The thumbnail looks ok I open the Jpeg in PS and I get this...

I get the same thing if I open the file with NC so it looks like NC is not saving the file properly.
Can anyone shed some light on this?