I've upgrade from Ubuntu FF to Ubuntu GG and I realize that there is some unexpected behavior when I select songs to change title. I am not so sure if this also occurs in Ubuntu FF because I don't remember I've encounter it. Here is what I did and the un-expected result.

1. Select Multiple songs
2. Right click and choose "Edit Tag title"
3. Press ESC to cancel
4. Click on a song  - this will make the selection of all the song in Step 2 to disappear and only the song that you click here shown as selected
5. Press F2 to change title of that song
6. Type in the new name and press ENTER

This should result in changing of the title of the only one file selected in the step 4 to change. Instead, the title of all of the songs that are chosen in the Step 2 to change.

This should be fixed obviously but for the moment this workaround to avoid it, select other song before selecting the song you want to change its title.