You're still playing the
BETA-TEST VERSION?!
YES! is the short answer to your question. When I played through all 4 Galleons, I found about 3 or 4 instances where that happened (usually because key 4 was marked in the map as key 5, or something similar). Obviously I fixed them all in the release version.
All is not lost however. When you download the release version, save your current data file and dizzy.ini file (the configuration settings file), and replace the ones you download with those two current files. That should allow you to carry on with Galleon 2.