After copying a small section of audio and moving it - it turns pink and has a red flag that reads something like "+4;13" on it. I figure it's a warning but can't quite track down what it means.
It highlights in pink when it's out of sync with the associated video. Since it's a duplicate copy and apparently you meant to move it, you can ignore the warning.
It does get a bit annoying because after a while you can't tell at a glance which things are out of sync and shouldn't be, and which things are out of sync because you want them to be. It would be nice if there was a right-mouse-button context command one could click to turn off the pink and warning in those situations.