Hey Dave,
Is their a small red rectangle appearing at the top of each clip in your thumbnails ?
If so that means the clips are linked and you can click either :
Batch Unlink (unlinks all clips and reverts back to the default blank grade)
or
Batch Copy (keeps the grade you have but will break the link)
I hope this helps!
Thanks,
D
Dan Moran
DaVinci Application Specialist
Blackmagic Design EMEA