Please attach ~/.freecol/freecol.log which might provide some more clue towards which particular "feature" of FreeCol causes this to happen.
Additionally, if it is possible to reproduce somewhat consistently (i.e. with slightly more details than "play for some time"), please attach a save game causing this to happen. That said, seems to be more of a JDK-issue than a FreeCol-specific. -- Andreas D. Landmark -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org