Tremolo copy bug

Using v1.0 with Windows 7
1. create a tremolo for two whole notes. See first file.
2. copy measure
3. paste measure to measure 2. See second file.
4. undo copy. (Deleting notes from 2nd & 3rd measures has the same result.) See third file.
First, the tremolo does not copy correctly.
Second, the third measure is now an empty measure unaccessible to add or copy to.
It still can be deleted, but that can be a pain if there are several staves above it because it will delete that measure from all staves.