Start The 7th Guest by loading a save directly from the ScummVM launcher (instead of starting the game and loading from the game menu). Then go to the game menu and click Save. The game asks you to select a slot to save, but the names of the existing savegames do not appear when hovering over the numbers.
I'm attaching a random savegame; load it from the ScummVM launcher to reproduce the bug.
Game version: The 7th Guest, DOS, English
ScummVM version: 1.0.0pre042960, Intel Mac, Mac OS X 10.5
Savegame
Can't see how this was missed originally. Fixed as of r43020.