Start up Black Ink. Notice the VM size -- about 120MB on my system (iBook G4, 10.4.10). Do a few puzzles, opening, solving, and closing one at a time. Check the VM size again -- it's up about 1MB/puzzle, maybe a little more. Not sure if this is a real leak or just fragmentation making the heap creep up.
This just happened to catch my eye as I went to see why the iBook was thrashing. Firefox was the real pig, with over 1GB of VM.