Something weird with copying

When I copy a couple of curves I find that some smaller curves which are selected doesn’t appear in the copy.
I work in 7.

Anyone has a clue?

when typing copy, it works okay. So I dont have a problem in my work.
But that looks like a bug as it did not happen in rhino 6

We would need to see a sample file. It’s more likely that your objects are just locked some way.