I am copying masks from one clip to another where I did cuts in my interviews, the mask is out of position from the previous clip. I am using paste attributes then selecting the color effects. I have been noticing this before, but now I need very precise masks and I can see where its not in its correct position after I paste it to the next clip. Anyone else having this issue.. or know of a workaround? Here is a video below of the problem.
I tried to repeat your problem, creating a color correction with 4 masks and pasted the attributes to another clip, as you do in your movie.
It works fine for me, but I noticed that if I change the scale of the other clip and then pasted the attributes then the masks where out for place.
So it seems that the position of the masks is relative to the scale (and maybe other parameters under Transform / Crop / Distort, but I haven't experimented more). Maybe you can find your problem there?
I tested to Paste attributes and checking both "Color" and "Transform" (all boxes) and then the mask got applied correct. But of course that changed the scale of the second clip and you will have to manually change that back afterwards. (Or duplicate the clip before pasting the masks, and then copy attributes from the duplicated clip and only paste the Transform-parameters back to the original clip. Then you delete the copy. Maybe that could work, even if it's awkward?).
If you have 5 clips from the same take and have made slight adjustments to crop/size then the masks would be applied at the wrong place if it worked otherwise.
It would be neat though if there was a choice to paste the attributes relative or not.
To make FCPX work the way you want you could first position/resize/crop all the clips. Then make a compound clip of each.
Then make the color corrections and masks to the first compound clip, copy and paste to the other compound clips. Since the compound clip itself isn't rezied or cropped you should have no problems with the mask.
I sent the bug to apple.. Hopefully they will fix it in the next update. I am just tired of all the hoops I have to jump through to make simple things work. Thanks for the help though man. Glad I got a response!