Pasting a passage with triplets pastes them as normal notes.

To reproduce:
1) 5 (crotchet entry), ctrl+3 (triplet), 4 (quaver entry), a, b, c.
2) copy and paste the triplet created above into the next bar.
The triplet is pasted as straight quavers.

When pasting longer passages that include triplets, the passage is "expanded" so that all notes are played, and thus the pasted passage will be longer than the copy source.
Using last night's revision.